LONDON — Many travelers returning to the U.K. from Greece will have to self-isolate as of 4 a.m. Saturday after most of that country was removed from the government’s safe list. Only the islands of Corfu, Crete, Rhodes, Zakynthos and Kos are still considered safe destinations and require no quarantine upon return.

In other efforts to control the virus, British government extended its ban on travel from Denmark for two weeks amid continuing concern about an outbreak of cases on mink farms that spread to some nearby communities.

The restrictions, which were imposed Nov. 7, allow only British citizens and residents of the U.K. to enter from Denmark, but they have to self-isolate for 14 days after arrival. However, the British government on Thursday announced an exception for Danish and Icelandic professional soccer players and staff who need to travel for international matches.

The government also said the United Arab Emirates, Qatar, Turks & Caicos Islands, Laos, Iceland, Cambodia, Chile and Bahrain have been added to the safe list of countries. Starting at 4 a.m. Saturday, passengers traveling to the U.K. from those places will no longer need to self-isolate as long as they haven’t been to or transited through non-exempt countries in the 14 days preceding their arrival.

The United Kingdom posted its biggest one-day jump in laboratory-confirmed coronavirus infections Thursday as the government reported 33,470 new cases.

That was 10,520 more than the number of positive tests reported Wednesday and pushed the total number of cases in the U.K. since the pandemic began to almost 1.3 million. More than 50,000 people have died from COVID-19 in the country, which is Europe’s deadliest toll.