MOSCOW, April 28 (RIA Novosti) - An air-to-air missile exploded Friday at an air base outside Moscow, killing two servicemen, the head of the Air Force said.

Vladimir Mikhailov said the explosion had occurred at 8.30 a.m (4.30 a.m. GMT) at a military base at Sergiyev Posad, 70 kilometers (43 miles) northeast of Moscow.

Mikhailov said the missile's engine had spontaneously combusted, causing the explosion, and added that an officer and a serviceman had died immediately.

"Several dozen missiles were delivered to the testing range for disposal by being exploded, but one of them exploded earlier than planned, killing Maj. Sergei Kurtin and Private Maksimov," he said, adding that an investigation was underway.