MOSCOW, Sept. 22 (Xinhua) — A Mi-8 helicopter of Russian Ministry for Emergency Situation and Civil Defense crashed southeast of Moscow Wednesday evening, killing all three crew members on board, officials announced.

The helicopter crashed in Lyubertsy district during a training flight on rescuing people in adverse circumstances, according to the regional branch of the Ministry for Emergency Situation and Civil Defense.

"The crashed helicopter caught fire and 100 specialists from Russian Ministry for Emergency Situation and Civil Defense were involved in the firefighting efforts," the regional branch said.

One "black box" was found in the tail of the helicopter and another one was found in the cockpit. The cause of the crash is yet to be determined.