A Russian Antonov military cargo plane has crashed on the border between Russia's Tula and Oryol regions, with all 11 crew members confirmed dead. The Russian military An-22 aircraft had been flying from the southern city of Voronezh to Tver, which is located north of Moscow, when it vanished from the radar screens, the Itar-Tass news agency quoted a source from the Russian Defense Ministry as saying early on Wednesday. According to a Russian law enforcement official, all 11 crew members on board the plane have been confirmed dead. A defense official has said the crash may have been caused by faulty aviation equipment. The Tula region is about 120 miles (193 kilometers) south of Moscow, and the Oryol region is about 225 miles (360 kilometers) southwest of Moscow.The Antonov An-22 planes were used by the Soviet Air Force and the Russian airline Aeroflot.Approximately 45 remained in service by the mid-1990s, mostly in the Russian Air Force. The aircraft can airlift up to 290 soldiers or 150 paratroopers or four units of heavy equipment.