A Russian military plane has reportedly crashed off the coast of Syria near a Russian air base, killing two pilots in what appears to be an accident.

Russia leases the Khmeimim air base in the coastal Latakia province, where it maintains fighter jets and bombers involved in a nearly three-year military campaign in support of the Syrian government.

The Sukhoi Su-30SM fighter jet crashed into the Mediterranean Sea after taking off from Khmeimim, Interfax reported Wednesday, citing the Russian Defense Ministry. One of the victims has been identified as Major Albert Davidyan.

The ministry said the crash was not caused by artillery fire.

“According to preliminary information, the cause of the crash could have been a bird hitting the engine,” Interfax quoted the ministry as saying.