Greece’s coast guard said the bodies of six people have been recovered from the shore of the eastern island of Lesbos on Tuesday, with authorities suspecting the people were migrants who died in their attempt to make it to Greece from the nearby Turkish coast.

The coast guard said the bodies of the three men and three women were found early Tuesday morning near the island’s main town of Mytilene.

There were no signs of a shipwreck, and the discovery of the bodies was not preceded by any call to emergency numbers about a boat in distress near the island, the coast guard said.

None of the six had been wearing life jackets.

A search and rescue operation was launched in the area with three coast guard patrol boats, a helicopter and nearby ships to look for potential survivors, while authorities were also searching the coastline.

Thousands of people fleeing conflict and poverty in Africa, the Middle East and Asia attempt to reach the European Union through Greece, with many making the short but often perilous journey in unseaworthy dinghies from the Turkish coast to nearby Greek islands.