Contact with the air traffic control was broken when the plane tried to land, reports the Russian news agency Tass, citing sources.
The plane is said to have been on its way from the town of Petropavlovsk-Kamchatsky to Palana in Kamchatka when it stopped answering calls.
At least one child on board
Russian news agencies are said to have received conflicting information about what happened.
One source tells Tass that the plane may have plunged into the sea, another tells Interfax that it may have crashed near a coal mine near the city of Palana.
A search operation has been launched, and at least two helicopters and rescue workers must be ready, according to reports.
Six crew members and one or two children must be among the 28 on board.
Russia used to be notorious for plane crashes, but has improved its safety statistics.
Problems with poor maintenance of aircraft and weak safety regulations remain, however, and several fatal plane crashes have occurred in recent years.
The most recent major accident was in May 2019, when a plane from the airline Aeroflot crash-landed and caught fire on the runway at an airport in Moscow.
41 people though.
The Far East is one of Russia's federal districts.
It covers large parts of the eastern lands.
It is considered an area where it can be dangerous to fly, due to severe weather conditions.