A Robinson helicopter has disappeared in the Romny District of Russia's Amur Region.
According to preliminary data, there were four people on board, according to the website of the regional Emergencies Ministry.
The helicopter took off from a logging site near the village of Amaranka and disappeared.
Its location remains unknown.
A search and rescue team and an airmobile unit of the Emergencies Ministry have been sent from Blagoveshchensk to the alleged crash site.
Thirty-six people and 12 pieces of equipment, including three snowmobiles and a drone, are participating in the search.