A small boat carrying migrants from nearby Turkey sank in wind-tossed waters in the eastern Aegean Sea just off the island of Samos, killing at least four people, Greek authorities have said.
The bodies of three women and a girl were found in the water following the incident on Monday.
The coast guard said five others were rescued from the sea, and another 26 who safely made it to shore were later found on land.
A large search and rescue operation by air, land and sea remained in effect because survivors said it was possible one or two people might still be missing.
Authorities were initially alerted by a local resident who heard screams and cries for help from the sea, local officials said.
It was not immediately known how the boat, believed to have been a small dinghy, sank, and there was no immediate information on the identities or nationalities of the survivors and the dead.
Sonia Balleron, the head of the Greece mission for the international medical charity Doctors Without Borders, said the group was “shocked and outraged” by the sinking and was providing emergency support to the survivors.
“These deaths are the tragic consequence of inhumane migration policies,” Ms Balleron said in a statement.
Human rights groups accuse European authorities of failing to provide legal migration paths for people seeking a better life on the continent.
Greece lies along one of the most popular routes into the European Union for people fleeing conflict and poverty in the Middle East, Africa and Asia.
Despite a crackdown by Greek authorities along the land and sea border with Turkey, thousands of people make it across, often from the Turkish coast to Greek islands using flimsy inflatable dinghies.
In recent months, smugglers have also increasingly turned to ferrying migrants in powerful speedboats.
