Greece's coast guard says a search and rescue operation is underway off the coast of the eastern Aegean island of Lesbos after a boat carrying migrants overturned.

The coast guard said Wednesday that two survivors had been rescued, and had told authorities they had been in an inflatable dinghy with another nine people when the vessel capsized as it headed to the island from the nearby Turkish coast.

Vessels from the Greek coast guard and the European border agency Frontex were searching for the missing.

Lesbos has been the main arrival point for hundreds of thousands of refugees and migrants heading to Europe. But numbers of new arrivals have fallen dramatically following a March deal between the Eurooean Union and Turkey to limit the refugee flow.