LONDON -- Hundreds of thousands of British holidaymakers in France face the prospect Friday of having to go into self-isolation for 14 days when they return home after the British government reimposed quarantine restrictions on the country following a recent pick-up in coronavirus infections there.

In an announcement late Thursday, the government said France is being removed from the list of nations exempted from quarantine requirements because of rising coronavirus infections, which have surged by 66% in the past week. The Netherlands, Malta, Monaco and the Caribbean islands of Aruba and Turks & Caicos are also being added to the quarantine list.

The requirement to spend 14 days in self-isolation will apply to anyone returning to the U.K. after 4 a.m. local time on Saturday, a timeframe that may prompt many to try to return before then. That could be particularly the case for anyone currently in France, which is the second-most popular holiday destination for British tourists.

Getlink, which operates train services in the Channel Tunnel, warned travellers that they may not be able to get back in time as services are heavily booked.

John Keefe, Getlink's director of public affairs, told the BBC that trains were "already pretty much fully booked" on Friday.

He said there was "some possibility of adding additional trains in the off-peak periods" but insisted that would-be travellers have to check online before heading to the terminal.

While the number of new infections in Britain is also rising, they are not thought to be increasing at the same pace as in the countries added to the quarantine list. The latest 14-day cumulative figures from the European Centre for Disease Prevention and Control show 32.1 COVID-19 cases per 100,000 people in France, compared with 18.5 in the U.K.

British Prime Minister Boris Johnson said Thursday that everyone "understands that in a pandemic you don't allow our population to be re-infected or the disease to come back in."

The decision is a big blow to France's tourism industry. The country has said that it will respond to the U.K. move in kind. Clement Beaune, France's secretary of state for European affairs, said in a tweet that the U.K. decision would lead to "reciprocal measures."