A school has moved a year group back to online classes after a rise in Covid cases.
MacMillan Academy in Middlesbrough, North Yorkshire is "really struggling with staffing levels" after Covid infections hit staff and students.
The school will also reinstate face masks in communal areas from Tuesday, Teeside Live reports.
In a letter to parents and carers, Head of School Rachel Coning wrote of making a "very difficult decision" to return Year 12 classes to online platforms until Friday.
Supply teachers have been filling the gaps left by sick staff but "it is not going to be enough for the rest of this week".
"It is not out of the question that we will have to ask another year group to also work from home later in the week, I will let you know if this needs to be the case," she added.
The letter states: "As recent communication has indicated, the number of COVID cases in the academy has increased recently and this has affected both staff and students.
"For the first time in the pandemic we are really struggling with staffing levels.
"Over the last week or so we have had to call on a number of supply teachers but even that is not going to be enough for the rest of this week.
"Therefore we have made the very difficult decision to move Year 12 students to online learning from tomorrow for the rest of the week.
"Year 12 have made a great start to the year and we know they will work very hard independently.
"We are also conscious that we do not want to create childcare issues for parents and that is why we have chosen Year 12.
"Unfortunately, due to the fact that staff in the building will be covering other lessons, we cannot deliver live Teams lessons to Year 12 and work will be set on Frog.
"If your child has any issues at all then please encourage them to get in touch with their teachers.
"It is not out of the question that we will have to ask another year group to also work from home later in the week, I will let you know if this needs to be the case.
The school has also been in consultation with Public Health England over the use of face masks in school.
The letter continues: "In addition, it will come as no surprise that in consultation with public health, from tomorrow we will be reinstating the wearing of face masks in all communal areas.
"Obviously if students are exempt or really do not want to wear a mask then they will not be forced to do so.
"If you could ensure they have a mask with them from tomorrow then that would be great.
"Please don’t worry if you don’t have any masks, we do have spares at the academy.
"As mentioned in my message yesterday, if you can continue to encourage your child to complete daily lateral flow tests then that will help to pick up asymptomatic positive cases."
A number of other schools have also reintroduced face masks this month.
Pupils at Conyers School have been told to wear masks again "at all times" in communal indoor spaces following multiple covid cases.
And All Saints Academy students have been told to wear masks "at all times" following a "significant" number of covid cases being detected.
