ATHENS, Greece — A search and rescue operation is underway Friday near Greece's island of Lesbos along the maritime border with Turkey, after an inflatable dinghy carrying migrants apparently sank, authorities said.

Ten people had been rescued and another three were believed to be missing, Greece's coast guard said.

Two coast guard patrol boats, a vessel from the European border agency Frontex, one helicopter and two aircraft, as well as a vessel that had been sailing nearby, were involved in the search operation, the coast guard said. Turkey’s coast guard had also been informed of the incident.

According to the Greek coast guard, the dinghy appeared to have sunk inside Turkish territorial waters, with initially one survivor swimming into Greek territorial waters and being picked up by Greek authorities. Another nine people were then also rescued, they said.

Survivors told authorities there had been a total of 13 people on the dinghy when it sank. Their nationalities weren't immediately available.

Greece has been one of the most popular entry points into the European Union for people fleeing conflict and poverty in the Middle East, Africa and Asia for years. The vast majority attempt to reach Greek islands near the Turkish coast, often in dangerously overcrowded inflatable dinghies and unseaworthy boats.