Greece has threatened to reintroduce some lockdown measures following a spike in Covid-19 cases that coincided with the return of tourism.
Greece has so far seen fewer than 200 deaths, but more people now have the virus than at any point during the pandemic.
The Telegraph reports 60 people were confirmed to have the virus on Friday, the highest number since late April. More than 100 new cases in the last fortnight have been among incoming tourists.
A Greek government spokesperson told local media the country was “determined to protect the majority from the frivolous few”.
There are no new measures affecting UK tourists, but Bulgarians passing into Greece must have proof of a negative test.
Greece is due to re-admit UK tourists from Wednesday (15 July).