A cargo ship sank off the Greek island of Lesbos in stormy seas early Sunday, leaving 13 crew members missing and one rescued, authorities said.

The Raptor, registered in the Comoros, was on its way to Istanbul from Alexandria, Egypt, carrying 6,000 tons of salt, the coastguard said.

It had a crew of 14, including eight Egyptians, four Indians and two Syrians, the coastguard said.

The ship reported a mechanical problem at 7am on Sunday, sent a distress signal and shortly after disappeared about four-and-a-half nautical miles south west of Lesbos, authorities said.

One Egyptian was rescued, a coastguard spokeswoman told the Associated Press.

She said that eight merchant ships, two helicopters and one Greek navy frigate were searching for survivors.

Three coastguard vessels had difficulty reaching the area because of rough seas, she added.

The spokeswoman spoke on condition of anonymity because the case was ongoing and she was not authorized to speak to the media.

Northwesterly winds in excess of 50 mph are blowing in the area, the national weather service said.