A cargo ship sank in the Marmara Sea off Istanbul after colliding with an oil tanker before dawn on Wednesday, leaving Turkish rescue teams searching for 10 crew members who were believed to have been on board.
The collision took place about 18 nautical miles, or 33 kilometres, off the Silivri district on the western edge of Istanbul province, according to the governor's office cited by Turkish maritime authorities. The ship that sank, the Tuğberk İmamoğlu, was carrying rolled steel when it struck the tanker ALSU. Officials said the cargo vessel stopped responding to calls shortly after the collision, and its crew could not be reached on mobile phones.
The maritime directorate said the first alert came from the ALSU's captain at 3:15 a.m. Search-and-rescue teams then sent 14 vessels and a helicopter to the area. The scale of the response suggests officials were dealing with an uncertain situation at sea, with the cargo ship unresponsive and the condition of the crew not immediately known.
Life-saving equipment from the Tuğberk İmamoğlu, including a lifeboat, was found at sea, but the 10 crew members were not inside it. That detail deepened concern that the sinking had happened quickly enough to separate the crew from the ship's emergency gear. Officials did not say in the supplied report whether any other debris or signals helped locate the vessel before it went down.
Officials said the ALSU was damaged in the collision and joined the search effort. The cargo ship was carrying 4,200 tons of rolled sheet metal at the time of the accident, according to the maritime directorate. The agency also corrected an initial report about the tanker, saying the ALSU was empty rather than carrying motor oil. That correction mattered because it narrowed the likely cargo and reduced early uncertainty around what the tanker had been transporting.
The sinking added to a difficult stretch for Turkish maritime authorities. It came three days after a deadly ferry accident off Turkish-occupied northern Cyprus, where eight Turkish nationals died and rescuers were still looking for 20 missing people.
For now, the immediate priority remained the search for the missing crew and the assessment of what caused the collision in one of Turkey's busiest sea approaches. The supplied evidence did not identify the cause of the impact or confirm whether the missing sailors had been found by the time of the report, and officials had not indicated a recovery.
