Turkey launched a search operation Wednesday in the Marmara Sea after a cargo ship sank following a collision with a tanker, leaving its 10 crew members unaccounted for, authorities said.

The Turkish-flagged Tugberk Imamoglu, a 90-meter (295-foot) dry cargo vessel, collided with the 91-meter (298-foot) Alsu, an oil or chemical tanker, at approximately 3 m. local time, the Istanbul governor's office said in a statement. The collision occurred a little more than 20 miles (32 kilometers) south of Silivri, a western suburb of Istanbul.

Search and Recovery Efforts

The Istanbul governor's office said contact was lost with the crew of the Tugberk Imamoglu after the collision, while the Alsu appeared undamaged. The office added that "numerous naval units from the coast guard's Marmara and Bosphorus Command and a coast guard helicopter were dispatched to the scene."

The Transport Ministry's maritime directorate said on X that the vessel was believed to have sunk "due to the Tugberk Imamoglu vessel failing to respond to any calls and the crew members' mobile phones not being answered." The directorate later stated: "It is assessed that the Tugberk İmamoglu vessel sank because it did not respond to any calls and the mobile phones of the personnel on board went unanswered."

A lifeboat and other debris belonging to the Tugberk Imamoglu have been found, but there is no sign of the crew, the General Directorate of Maritime Affairs said in a statement. An emergency signal was received from the vessel, and the first rescue craft reached the site at 4:10 , according to the directorate.

Transport Minister Abdulkadir Uraloglu said: "There are 10 seafarers on board, including the captain. They are all Turkish. We can say that the sinking occurred rapidly in 11 minutes. No one has been found alive." He did not provide further details on the crew's status.

Two helicopters and 12 search and rescue vessels are searching the area, the authorities said.

Vessel Details and Context

The Tugberk Imamoglu was traveling from Turkey's Mediterranean port of Iskenderun to Eregli in the Black Sea, according to the Istanbul governor's office. Deutsche Welle reported the port was Karadenizeregli. The vessel was carrying 4,199 tons of coiled steel, according to the maritime directorate.

The Alsu, which was sailing from Kocaeli, east of Istanbul, to Aliaga on the Aegean coast, did not appear to have suffered any damage in the collision, the governor's office said, citing the Marine Traffic website for the vessel details.

The rescue operation comes as Turkish naval units are helping search for a passenger ferry that sank off the coast of Cyprus on Sunday. Eight people died when the Filo Jet sank, and 20 remain missing.

The Turkish Straits, comprised of the Bosphorus Strait and Dardanelles Strait at either end of the Marmara Sea, are among the busiest shipping lanes in the world, with hundreds of thousands of vessels transiting between the Mediterranean and Black Seas yearly.