BERLIN (AP) — Authorities are conducting a search and rescue operation off the southwestern tip of Greece for a boat believed to be carrying dozens of migrants, after a passenger made a distress call to an emergency number.

Three Greek coast guard vessels and a plane from the European border agency Frontex are searching the sea Thursday to the west of Pylos, on the southwestern tip of the Peloponnese, the coast guard said.

The passenger who called emergency services reported that the vessel was carrying around 60 people and had run into unspecified trouble.

Greece is still on one of the most popular routes for refugees and migrants attempting to enter the European Union, although the vast majority arrive on eastern Aegean islands from the nearby Turkish coast.