Greece's coast guard says six bodies have been recovered from the sea off the eastern Aegean island of Lesbos, while one person has been rescued.

The coast guard said a Greek navy vessel located the bodies, believed to be of migrants attempting to enter Greece from Turkey clandestinely, on Monday. Five were recovered by the European border patrol agency Frontex, while one was recovered by the coast guard.

The six dead were one man, four women and a boy. The coast guard rescued a pregnant woman from the water and transported her to Lesbos.

It was unclear how many others might be missing in the incident. Vessels from the Greek coast guard and navy, Frontex and a private boat have undertaken a search operation.