Ten crew members are feared dead after a Turkish cargo ship sank following a collision with a tanker in the Marmara Sea off Istanbul early Wednesday, authorities said.

The 90-metre cargo ship, Tugberk Imamoglu, sank after colliding with the Turkish-flagged tanker Alsu at around 3 a.m., according to Turkey's General Directorate of Maritime Affairs.

A lifeboat and other debris from the cargo ship have been found, but there was no immediate sign of the 10 crew members.

Transport Minister Abdulkadir Uraloglu said all those on board, including the captain, were Turkish nationals.

“The sinking occurred rapidly in 11 minutes. No one has been found alive,” he said.

Two helicopters and 12 search-and-rescue vessels were deployed to search the area.

The collision took place about 32 kilometres south of Silivri, a western suburb of Istanbul. The cargo ship was carrying rolled steel and was travelling from the Mediterranean port city of Iskenderun to Eregli on the Black Sea.

Authorities said an emergency signal was received from the Tugberk Imamoglu, and the first rescue vessel reached the area at around 4:10 a.m.

Officials said they believe the ship sank after it stopped responding to calls and the mobile phones of crew members could no longer be reached.

The 91-metre Alsu, an oil or chemical tanker, was travelling from Kocaeli, east of Istanbul, to Aliaga on Turkey's Aegean coast.

The search operation comes just days after Turkish naval units joined efforts to find passengers missing after a ferry sank off the coast of Cyprus on Sunday. Eight people were confirmed dead and 20 others remained missing.

The Turkish Straits, including the Bosphorus and Dardanelles, are among the world's busiest shipping routes, with hundreds of thousands of vessels passing between the Mediterranean and Black Seas every year.