Germany's health authority announced late Saturday that Britain had been added to its list of Covid high-risk countries, which will mean tighter travel restrictions.
The decision is a response to the rapid spread of the Omicron variant, which forced London's mayor Sadiq Khan to declare a "major incident" on Saturday in the British capital, AFP said.
The change, which takes effect at the end of the day Sunday at midnight, means arrivals from Britain will have to observe a two-week quarantine regardless of whether they are vaccinated, said the country's health agency, the Robert Koch Institute (RKI).
The United Kingdom is now considered a "variant zone" of Covid-19, a category reserved for nations where the risk is the highest.
"The United Kingdom and Northern Ireland are very strongly affected by Covid-19. A new variant, very contagious, has also been found," the Germany Ministry of Foreign Affairs said on its website.
More than 65,000 new Covid cases were confirmed in London over the past seven days, with 26,418 cases reported in the last 24 hours -– the highest number since the start of the pandemic.
That is why these territories, including the Isle of Wight and the Channel Islands, have been placed for 14 days in the category of areas at very high risk, it said.
In addition to the quarantine measure, only German nationals or foreigners residing in Germany will be allowed to come to the country from Britain.
The rule applies to all means of transport and a PCR test will be required for all persons travelling to Germany.
Berlin's new health minister Karl Lauterbach has already sounded the alarm in the face of the risk of a new wave that could soon sweep over the country, hard-hit since the beginning of the autumn.
"The more we can push back... the better," he said on Saturday.
Several other European countries, including France, have already taken steps to limit the entry of travelers from the United Kingdom.
Meanwhile, German authorities have placed France and Denmark among the "high risk" contamination zones, a level below the UK.
