The UK government has dropped its plan to reopen primary schools to all pupils in England before the summer holidays amid concerns about the rate of coronavirus infections in the country.
Gavin Williamson, the education secretary, said schools would instead be asked to take in whatever number of children they can while keeping to rules on maximum class sizes of 15 pupils and social distancing.
It came as a study based on satellite data showing an increase in traffic around Chinese hospitals suggested that Covid-19 could have been present in China last summer.
Follow the latest updates
Secondary schools may not fully reopen until later than September
Matt Hancock has said secondary schools in England may not fully reopen until later than September despite saying coronavirus is "in retreat" across the UK.
Boris Johnson will speak with his Cabinet on Tuesday morning before the education secretary, Gavin Williamson, delivers a statement to Parliament on the wider reopening of schools.
Mr Hancock said at the Downing Street briefing that it was still "our current working plan" that secondary schools in England will not open until September "at the earliest".
The Department of Education said it remained the "ambition" for all primary school children to return before the summer holidays, but did not deny reports Mr Williamson will accept this desire may not be fulfilled.
With the number of new deaths falling to the lowest reported since lockdown began, Mr Hancock said plans to further ease restrictions including the reopening of non-essential shops from Monday could go ahead.
"When you look across the board, it is clear that coronavirus is in retreat across the country," he said, as deaths linked to Covid-19 reached nearly 51,000.
But with the phased reopening of England's schools having begun last week, he acknowledged older pupils could still face months without attending class.
"That is our current working plan, is that secondary schools won't open until September at the earliest," he said.
Children in England began returning in a phased process last week, with Reception, Year 1 and Year 6 pupils heading back first.
Mr Hancock has also unveiled plans for pupils and teachers across England to receive coronavirus testing to monitor the spread of the disease as classes resume.
With approval from parents and guardians, children will be tested to see whether they have Covid-19 or have had an infection in the past under the surveillance programme.
Mr Hancock is aiming to have up to 100 schools tested across England by the end of the summer term, with around 200 staff and children involved at each of those schools.
Coronavirus may have been in China in summer, study suggests
A study based on satellite data showing increased traffic around Chinese hospitals suggests the virus may have been present there last summer.
Researchers at the Harvard Medical School told ABC News the traffic increase "coincided with" elevated queries on a Chinese internet search for "certain symptoms that would later be determined as closely associated with the novel coronavirus."
“Something was happening in October,” Dr John Brownstein, the Harvard Medical professor who led the research.
“Clearly, there was some level of social disruption taking place well before what was previously identified as the start of the novel coronavirus pandemic.”
Schools trust welcomes reports ministers will abandon plans for all primary school children to return this year
Ian Robinson, chief executive of the Oak Partnership Trust, said he welcomed reports that ministers were going to abandon plans for all primary school children to return to classrooms before the academic year is out.
His trust runs three primary schools and a special school in Taunton, Somerset.
Mr Robinson told BBC Radio 4's Today programme: "I do welcome this announcement that is hopefully going to be made today.
"It demonstrates that the Secretary of State and the Department for Education are listening to the profession - I believe they have listened to the profession and this is a really positive step forward."
He added: "I think they are saying if you can extend your provision to other year groups then you can go ahead, but you still have to do it within the measures of control that are in place.
"And from my own trust's point of view, it is all about simple practicalities, it is not about whether you want children in schools or not.
"We simply don't have enough physical space for any more year groups and we don't have any more human resources for any more year groups."
Reports government is dropping plan to get all primary school years back to school before end of term 'a huge disappointment', children's commissioner says
Anne Longfield, the children's commissioner for England, said reports that the government is dropping the plan to get all primary school years in England back to school before the end of term is "a huge disappointment".
She told BBC Breakfast: "I think it's a huge disappointment for those children who'd expected to go back into school before the summer now may not.
"It does mean that the vast majority, probably about eight million children, very likely won't return to the classroom until September, which means that, again, there will be a huge variation in their learning over that period."
She said children will remain "isolated", with many living in "fragile" family environments.
"I hope that Government doesn't just write off this period," Ms Longfield said.
Turkish Airlines offers health professionals 40% discount
Turkish Airlines is offering health professionals worldwide a 40 per cent discount on flights through to May 2021, travel correspondent Simon Calder reports.
The Istanbul-based carrier serves a wide range of African and Asian destinations.
Calls for government to reconsider amid reports ministers will abandon plans for all primary students to return
Robert Halfon, chairman of the Commons Education Committee, has called for the government to reconsider after reports emerged that ministers are set to abandon plans for all primary school year groups to return before the end of the summer term.
The Conservative MP told BBC Radio 4's Today programme: "I think the government should definitely think again on this and continue with a phased reopening of schools because I think too many disadvantaged children are not getting an education."
He added: "We could have an epidemic of educational poverty and be damaging the life chances of hundreds of thousands of young people."
The former minister called for efforts to be made to educate children across the summer, including lessons broadcast through national media outlets.
"We are potentially facing kids not learning for 40 per cent of the school year and this has a massive effect, every statistic shows, on attainment and their life chances in the future," he said.
Mr Halfon continued: "I appreciate that not all schools can open because they may have old buildings, it may be very difficult.
"But just because you can't do it everywhere, it doesn't mean you shouldn't open schools anywhere."

Plans for all primary school pupils in England to return before summer look set to be abandoned
Plans for all primary schools children to return to school in England before the summer holidays are set to be abandoned by the government due to concerns over social distancing, political correspondent Ashley Cowburn reports.
It comes after some schools began a phased return of pupils on 1 June – including reception, year one and year six – almost two months after Boris Johnson ordered the closures of schools due to the coronavirus pandemic.
Under proposals to re-open schools, the government’s plan was “for all primary school children to return to schools before the summer for a month if feasible” – a position it said would be kept under review.
On Tuesday, the Department for Education (DfE) said it was still the “ambition” for a return of primary schools before July, but added Gavin Williamson will provide an update on the plans later today.
According to the BBC, the education secretary will tell MPs in a Commons statement that primary schools will no longer have to prepare for a full return of children before the summer holidays due to social distancing requirements.
British drug company expecting clinical studies on two antibody-based therapies
British drugmaker AstraZeneca has said it expects to move two Covid-19 antibody-based therapies it has licensed from US researchers into clinical studies in the next two months as it ramps up efforts to help combat the pandemic.
The company, which has a potential coronavirus vaccine in its pipeline, said it has agreed terms with the Defense Advanced Research Projects Agency and the Biomedical Advanced Research and Development Authority to back its project to develop a monoclonal antibody treatment against the virus.
Labour welcomes reports of government backtracking on calls for all primary pupils to return this year
Shadow education secretary Rebecca Long-Bailey has said Labour welcomed reports that the government was preparing to row back on calling for all primary school pupils to return during this academic year.
She said: "If the government confirms today that it will not be mandating reopening of schools in full before the summer this will be welcome.
"For weeks headteachers, education unions, school staff and many parents have stated that the plans to open whole schools before the summer could compromise any safety measures a school had been able to implement with reduced pupil numbers.
"The government has completely failed to show leadership.
"They should have brought together all those who needed confidence in their plans, from education unions and local authorities through to parents' associations.
"The government must now give answers on what resources it will provide to adequately support home learning, from the provision of digital devices to all pupils who need one through to targeted online tuition."

Official coronavirus death toll for England and Wales reaches 45,000
The death toll from coronavirus in England and Wales has now reached more than 45,000, according to the Office for National Statistics.
New data today shows that up to the 29 May there were a total of 45,748 deaths registered in England and Wales where Covid-19 was mentioned on the death certificate.
In care homes the number of deaths has now reached 13,454 by the 29 May.
The ONS said the latest weekly deaths showed the numbers were consistently falling with 2,464 fewer than the previous week but still 1,653 deaths higher than the five-year average.
Government plan for reopening schools 'ill-considered, premature and unworkable'
Nasuwt general secretary Patrick Roach said it has been "abundantly clear" that the government's dates for reopening schools were "ill-considered, premature and unworkable".
"The government's rush to seek to reopen schools as part of wider efforts to restart the economy has been in the face of deep concerns and mounting evidence that this would contribute to a second wave of infections and deaths from the coronavirus," he said.
Dr Roach added: "The overwhelming majority of teachers remain extremely worried that with schools opening to more children whilst safe social distancing and PPE continue to be major concerns, wider school reopening is simply not safe.
"In the absence of definitive guidance from the government, many schools have struggled to understand what they need to do in order to meet appropriate health and safety standards when they do reopen."
He said the government must now accept that its plans for wider reopening of schools are "no longer credible".
UK 'strange country' for prioritising pubs over schools, Tory MP says
Tory MP Robert Halfon said the UK is a "strange country" for prioritising reopening pubs over ensuring children could continue their learning in school.
Speaking to BBC Radio 4's Today programme, the Commons Education Committee chairman said he is "sympathetic" to Children's Commissioner Anne Longfield, who said the country should put the same effort it had into reopening pubs as thinking of ways to allow schools to operate safely.
"I think we're a strange country in which we turn a blind eye to mass demonstrations all over in every city, we campaign for pubs and cafes to open and yet we say to open schools before September is too risky when all the evidence - from the World Health Organisation, from many other European countries, from the chief medical officer in the UK - suggests otherwise," he said.
"We are potentially damaging children's life chances."
A chart comparing the best and worst rated coronavirus responses by Statista.

Travel firms say 14-day self-isolation for travellers will be neutralised by 29 June
A group of more than 500 travel businesses has received “private assurances from senior government sources” that the quarantine law, imposed on Monday, will be neutralised by the end of June, travel correspondent Simon Calder reports.
The policy was introduced by the home secretary, Priti Patel. Almost all arrivals at UK airports, ferry ports and international rail terminals are obliged to self-isolate at home for two weeks.
Ms Patel said: “These measures are informed by science, backed by the public and will keep us all safe.”
While the measures have initially been imposed for a year, the government has said they will be reviewed every three weeks. The first review date is 29 June.
The effect has been to stifle inbound and outbound tourism for the summer. The three big airlines serving the UK – British Airways, easyJet and Ryanair – have launched a legal challenge.
Australian state government allows football match but not Black Lives Matter rally
An Australian state government said it will allow 2,000 fans to attend an Australian rules football match but will not allow a Black Lives Matter rally on the same day.
South Australia is the first state or territory to allow a crowd to return to professional sport. Competitions have resumed in empty stadiums as the pandemic lockdown is being lifted.
South Australia police commissioner Grant Stevens said a crowd will be allowed at the Adelaide Oval on Saturday for a match between local teams Port Adelaide and the Adelaide Crows.
But police would not allow a second exemption for a protest against the death of George Floyd after allowing 5,000 demonstrators to gather last week.
"We acknowledged the unique and exceptional circumstances of the protests we saw Saturday. The public sentiment around the horrific events we saw in the United States and it was appropriate we gave consideration to that," Mr Stevens said of the exemption.
"To continually allow people to disregard the restrictions we have in place would make a mockery of the good efforts of everybody else who are doing their best to abide by those restrictions," he added.

UK economy will not recover from coronavirus unless 'radical new approach' taken, warn scientists
The government’s test, track and trace system is “not fit for purpose” and Britain will not recover economically from the Covid-19 crisis unless a radical new approach is taken to it, an eminent independent group of scientists has warned.
It will be “impossible” under the centralised system introduced by Matt Hancock to trace the necessary 80 per cent of contacts required to eliminate coronavirus, said the Independent Sage group led by the government’s former chief scientific adviser David King.
And the group warned that the “erosion of trust” in government over recent weeks - particularly among ethnic minority communities - is likely to have a "major" impact on undermining compliance with the scheme.
Spain 'not discussing' travel corridor with Britain
Spain is not discussing any travel corridor with Britain, a Spanish foreign ministry source told Reuters after a UK tourism lobby group said corridors allowing unrestricted movement with a number of countries would open from 29 June.
Spain is discussing with other European Union countries whether and how to allow tourism from Britain and other states, the source said.
Madrid hopes the EU will agree on common criteria over the coronavirus situation in a territory in order to allow tourists to travel, but will adopt its own criteria if there is no agreement at EU level, the source said.

Up to a third of all Indians living in 'hotspot' cities may have caught coronavirus, survey finds
Up to a third of people living in the containment zones of India’s ‘hotspot’ cities may already have been infected with Covid-19, according to the preliminary findings of a leaked report, Samuel Lovett reports.
The results of a population-based blood survey conducted by the Indian Council of Medical Research (ICMR), obtained by The New Indian Express, indicate that between 15-30 per cent of people in these high-risk areas have been exposed to the virus and recovered unknowingly.
After the research was leaked, the ICMR warned that the findings were “speculative” and had “yet to be finalised”.
The New Indian Express claimed blood samples had been collected from 10 hotspot cities, including Mumbai, Delhi, Kolkata and Jaipur, which account for nearly 70 per cent of India’s overall number of cases.
In total, nearly 24,000 samples from 70 districts across 21 states — including the 10 hotspot cities — have been acquired and tested at random. The data for at least eight districts are still reportedly being analysed and will be added in the final report, which is due to be published this week.
Lockdown prevented up to 3,500 prison deaths, minister says
Prisons minister Lucy Frazer said 2,500 to 3,500 deaths would have occurred in prisons had strict lockdown measures not been taken.
Shadow justice secretary David Lammy said: "As children in the general population continue returning to school, those in youth offender institutions remain locked up in their cells for almost the whole day without any access to education."
He added: "As the Government prioritises returning children to school, will she give me a date by which she expects all children in custody will have access to education, activities, family and professional visits?"
Ms Frazer replied: "He is right to identify that in the youth estate, like in the adult estate, we took severe measures when we realised we were facing a pandemic and we took those measures to save lives.
"We were looking at 2,500 to 3,500 deaths across the estate and so we took drastic action that we considered very carefully which resulted, he is right to say, in a severe lockdown. And the result of that, although every death is tragic, we have only suffered 23 deaths in our prison estate."
She added: "I am pleased to say that time out of cell has increased as the lockdown has continued and in YOIs children are now let out between two and three-and-a-half hours every day."