Moscow, SeC 9 (IANS/RIA Novosti): At least four people were killed when a Mi-35 combat helicopter crashed in a mountain in southwestern Russia's Dagestan region.

The four were found dead at the site of the incident, a law enforcement source said.

The combat helicopter crashed into the mountain while flying over it in poor weather conditions.

The Russian defence ministry reported that there were three people on board. The ministry suspended Mi-35 flights after the incident.

According to the source, the fourth person was not a crew member. There were no other injuries or damage on the ground.

"The names of three crew members who were on board of the helicopter are known. But there is a possibility that one or two people could be on board. The exact number of killed in the crash is unknown," the source said.

"According to reports, the helicopter has not been shot down, poor weather conditions were the cause of the crash," said a defence ministry spokesperson.