ISTANBUL – A Turkish cargo ship sank in the Marmara Sea near Istanbul after colliding with a second vessel, with rescuers searching for its 10 crew members, Turkish officials said on Sept 2.

The incident occurred before dawn when the ALSU, an empty oil tanker, collided with the Tugberk Imamoglu, a cargo ship carrying rolled steel, which sank shortly after, the transport ministry’s maritime directorate said on X.

“Due to the Tugberk Imamoglu not responding to any calls and the crew not answering their mobile phones... it is believed the dry cargo ship has sunk,” it said.

The collision occurred 18 nautical miles off Silivri district on the western edge of Istanbul province, with Transport Minister Abdulkadir Uraloglu telling journalists the damaged vessel had sunk “very quickly”.

“We received the emergency call at 0326. If we accept the captain’s reported time of 0315, we can say the sinking occurred very rapidly, within just 11 minutes.

“We spotted life buoys and a lifeboat but it was empty. Unfortunately, no survivors have been found so far. Search and rescue operations are continuing by sea and air,” he said.

He said there were 10 people on board: the captain and nine crew members, all of them Turkish nationals.

The cargo ship went down in waters that were approximately 900m deep, with 14 vessels and a helicopter involved in search and rescue efforts, the maritime directorate said.

“Life-saving equipment, including a lifeboat belonging to the Tugberk Imamoglu which had 10 crew members on board, has been found at sea. Unfortunately, the crew members were not inside,” it said.

The ALSU, which was damaged in the collision, was also participating in search and rescue efforts, it said.

According to the VesselFinder tracking website, the Tugberk Imamoglu is a Turkish-flagged cargo ship built in 1990 which is 90m long.