A Turkish cargo ship carrying 10 crew members sank on Wednesday after colliding with a tanker off the coast of Istanbul, with no immediate signs of survivors, Turkish authorities said.

A lifeboat and other debris from the Tugberk Imamoglu have been found, but there has been no sign of the crew, Turkey's General Directorate of Maritime Affairs said in a statement.

“There are 10 seafarers on board, including the captain,” Transport Minister Abdulkadir Uraloglu said. “They are all Turkish. We can say that the sinking occurred rapidly in 11 minutes. No one has been found alive.”

Two helicopters and 12 search and rescue vessels were searching the area.

The ship collided with the Turkish-flagged tanker Alsu in the Marmara Sea at around 3 am (2 am CEST), according to the General Directorate of Maritime Affairs. An emergency signal was received from the Tugberk Imamoglu, with the first rescue vessel reaching the area at around 4:10 am (3:10 am CEST).