ATHENS: Greece's south Aegean islands were marked 'dark red' on the European Centre for Disease Prevention and Control's COVID-19 map on Thursday after a rise in infections, meaning all but essential travel to and from the region is discouraged.

The cluster of 13 islands includes Greece's most popular destinations for foreign tourists - Mykonos, Santorini and Rhodes - which, combined, draw millions of people every summer.

Greece had relied on promoting "COVID-free" islands to draw visitors back this summer, hoping a rebound in international travel would resuscitate its vital tourism industry after its worst year in decades in 2020. Despite a strong June in terms of arrivals, uncertainty remains over how the season will unfold.

"We're waiting to see how the (tourist) markets will react," said Manolis Markopoulos, president of the hoteliers association of Rhodes, where more than 90% of tourists are from abroad, referring to the ECDC decision. The ECDC is an agency of the European Union

Germany and Britain are the biggest sources of visitors to Greece.

The dark red zones on the ECDC map help distinguish very high-risk areas and also helps EU member states uphold rules requiring testing on departure and quarantine upon return.

Last week it downgraded Crete, Greece's biggest island and another popular destination, to the dark red zone.