The Russian military said one of its helicopters crash-landed in an uninhabited area north of Moscow late Tuesday, killing all crew members.
The Defense Ministry said the incident involving a Mi-8 helicopter occurred near the town of Klin, about 90 kilometers (56 miles) from Moscow. The incident may have been caused by a technical malfunction, officials said.
The ministry didn't clarify how many crew members were on board, but said that the helicopter wasn't carrying ammunition and landed "in a desolate area."
The Chief Command of the Russian Aerospace Forces has dispatched a commission to the site of the incident, officials added.