Greece quarantined a migrant camp after 20 asylum seekers tested positive for coronavirus, the migration ministry said.
Tests on 63 people were conducted after a 19-year-old female migrant who gave birth in Athens was found infected, the first recorded case among asylum seekers in overcrowded migrant camps country-wide.
No confirmed cases had any symptoms, the ministry said and it was continuing tests.
Movement in and out of Ritsona camp, north-east of Athens and holding up to 2,500 people, will be restricted for 14 days the ministry said, adding police will monitor implementation of the measures.
Earlier this week, authorities were trying to trace where the woman was infected and looking at the possibility it may have been at the hospital.
The camp has an isolation area for coronavirus patients should the need arise, ministry sources had said.
Greece recorded its first coronavirus case at the end of February and reports 1 415 cases to date. Fifty people died.
The country is a gateway for migrants and asylum seekers fleeing war and poverty in the Middle East and beyond, with more than a million going through the country in 2015-2016.
Over 40 000 asylum seekers are in overcrowded refugee camps on the country’s outlying islands in conditions aid organisations say are appalling and which government describes as a “ticking health bomb”.