Three people are missing in Istanbul after a Turkish-flagged fishing boat collided with a Russian-flagged tanker on the Bosphorus Strait on Friday, according to Istanbul Governor’s Office. 

The collision took place at around 6.35 a.m. local time (0335GMT) off Istanbul’s Sariyer district, according to a statement by the local governor’s office.

The fishing boat sank after the collision. Authorities were able to rescue three out of the six people on board.

The cause of the incident remains unclear, with rescue efforts underway for the remaining victims.

Anadolu Agency website contains only a portion of the news stories offered to

Read more: Turkey: 3 missing after boat, tanker crash on Bosphorus