Six crew have died after a Turkish general cargoship broke in two and sank off the country's Black Sea coast on Monday.

The AP news agency said the 3,500-dwt Volgo Balt 214 (built 1978) went down off Samsun in rough seas.

Seven other seafarers were rescued.

The Samsun governor's office said a distress signal had been received from the vessel, which was heading into the port from Azov in Russia.

Governor Osman Kaymak told reporters after visiting the survivors in hospital that six crew members, including the captain, died before rescuers could reach the area, ABC News reported.

He quoted one of the survivors as saying that the hull split in two after being hit by a powerful wave.

The crew included 11 Ukrainians and two Azerbaijan nationals, Kaymak said.

The Turkish Coast Guard sent a plane, three helicopters and two ships to the site.

The vessel is managed by Orbital Shipmanagement of Turkey.