Four people were killed when a Mi-35 combat helicopter crashed in a mountain on Saturday in the North Caucasus republic of Dagestan, a law enforcement source said.

“Four people were found dead on the site of the incident,” the source said.

The combat helicopter crashed into the mountain while it was flying over it in poor weather conditions. Earlier the Defense Ministry reported that there were three people on board. The Defense Ministry suspended Mi-35 flights as the result of the incident.

According to the source the fourth person was not the crew member. He added that 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,” a spokesperson of Russia’s Defense Ministry said.