Russia is developing underwater drones for special tasks, a senior defense industry official said on Friday.

“The U.S. Navy is moving along similar lines,” said Anatoly Shlemov, head of state defense contracts at the United Shipbuilding Corporation.

Although work on those systems began in the USSR in the late 1980s, this is the first time it has been officially announced.

That was why the Soviet Navy abandoned the Piranha submarine program, Shlemov added.

Project 865 Piranha (NATO reporting name Losos) is a midget submarine, designed for special operations and is almost completely silent.

Only two Piranha-class submarines were reportedly built.