MOSCOW (AP) — The Russian military says Russian warships in Eastern Mediterranean have driven away a Dutch submarine shadowing the squadron.

Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said two Russian navy destroyers spotted the Walrus-class submarine Wednesday while it was 20 kilometers (some 11 nautical miles) away from the Admiral Kuznetsov aircraft carrier and escorting ships.

Konashenkov said the destroyers had tracked the submarine for more than an hour before forcing it to leave the area. He didn’t elaborate how the warships prompted the submarine to leave.

The spokesman added that such “clumsy” attempts to maneuver close to the Russian squadron could have resulted in an accident.

Konashenkov said the Russian squadron had previously spotted several NATO submarines, including a U.S. Virginia-class nuclear submarine, while en route to Eastern Mediterranean.