Eighteen illegal alien migrants drowned when their boat overturned 26 miles (40 kilometres) south of the southern Greek island of Chrysi, a coast guard official said on Saturday, while two were rescued from the sea.
The boat was initially detected by a Turkish cargo ship, which contacted the Greek authorities.
The survivors were being taken to the island of Crete, the official added.
Greece was on the front line of a 2015-16 migration crisis when more than a million people from the Middle East and Africa crossed into Europe.
Flows have ebbed since then but the last year has seen a steep rise in illegal immigrant boats, mainly from Libya, heading for Crete, Gavdos and Chrysi - the three Aegean islands nearest to the African coast. Fatal accidents remain common.
(Reporting by Lefteris Papadimas; Editing by Kevin Liffey)
