A second batch of Su-34 bombers has been turned over to the Russian air force by Sukhoi under a 2013 delivery contract.

The Su-34, designated "Fullback" by NATO, is a twin-seat bomber with a speed of 1,375 miles per hour at altitude and an altitude ceiling of 42,400 feet.

It has 12 hard points on its wings and fuselage for carrying bombs and missiles.

Sukhoi said the handover took place Tuesday at its factory in Novosibirsk and the three aircraft then flew to their deployment base or bases.

Three of the front-line bombers had been delivered to the air force in May.

"Implementation of the 2013 state defense order at the Novosibirsk aircraft plant is in full swing," the company said. "The company's management noted a high degree of readiness of aircraft, which is the guarantee of a full and timely implementation of the 2013 state defense order."

Orders for the aircraft were placed by Russia's Ministry of Defense in 2008 and 2010, the company said, but no other details were provided.