The country has seen infections increase this month to levels last seen in April, with officials blaming overcrowding in clubs and social events.

"We are calling this a wake-up week. We are trying to awaken people with messages and daily  announcements on additional measures," government spokesman Stelios Petsas told Mega TV.

"The virus is here, it feeds on our complacency," he said.

Over 380 new infections have been announced in August by the national public health organization.

Only 10 percent of cases in Greece can be traced to foreign arrivals, Prime Minister Kyriakos Mitsotakis told a cabinet meeting on Wednesday.

Greece has so far recorded 209 COVID-19 deaths and over 4,800 infections.

"We have located three sources of concern: very regular crossings from Balkan countries by ethnic Greeks and residence permit holders... social gatherings, including clubbing youths, weddings and baptisms, and public transport," Petsas said.

The public protection agency last week said masks must be worn in all indoor public areas, and visits to retirement homes and other institutions hosting vulnerable groups are restricted until August 15.

A limit of 100 guests was also set for weddings, baptisms and funerals, and summer fairs were cancelled.

Mitsotakis has already ruled out a general lockdown after gradually reopening the economy in May and starting to accept foreign arrivals in June to salvage part of the tourism season that is vital to the economy.