Two Su-34 fighter-bombers have collided mid-air during flights in Russia’s Far East on Friday, according to a source in the regional law enforcement agencies.

“Two Su-34 aircraft flying from the sea collided mid-air. The crew of one aircraft ejected. The fate of both crews is unknown yet,” he said.

According to the source, “the incident occurred about an hour ago.”

The Russian Defence Ministry confirmed information about the mid-air collision.

“The aircraft crews have ejected. An An-12 and two Mi-8 helicopters from the search and rescue forces are searching for the pilots in the area where they ejected. The planes performed the flight without ammunition,” the Russian Defence Ministry said in a statement.

At around 11:00 Moscow time, the search and rescue helicopter rescued one of the Su-34’s pilots on the life raft at sea with adverse weather conditions.

Later, rescuers managed to find the second pilot of the Su-34.

Flights of the Sukhoi Su-34 fighter-bombers have been suspended throughout Russia following an accident in the Far East, a source in the Russian Defense Ministry told TASS on Monday.

Based on the Soviet Union’s potent Su-27 air superiority fighter, the Su-34 Fullback is the Russian Air Force’s long-range strike aircraft of choice.

The Su-34, dubbed “Fullback” by NATO, is one of Russia’s most capable aircraft — able to engage targets on the ground and in the air — and has been used extensively in Syria.

The 45 ton, Mach 1.8-capable Russian Su-34, designed to carry up to 8 tons of weaponry, has a tactical radius of 4,000 km, and a flight ceiling of 18,000 meters.

The plane can also be equipped with up to three additional fuel tanks, allowing it to fly 8 hours without refueling.

*This is a developing story. More details will be added as they emerge.