The An-26 aircraft lost contact with air traffic control shortly before it was due to land in the settlement of Palana, in the north of the remote Kamchatka peninsula.
It is thought unlikely that anyone survived the crash.
The plane was flying from the regional centre Petropavlovsk.
Officials said that communication with the plane had been lost 9km (5.5 miles) from Palana airport, 10 minutes before it was scheduled to land.
Unconfirmed reports say it hit a rock as it was coming in to land. It is thought that it then crashed on the coast.
In a statement posted on the Kamchatka regional government's website, Governor Vladimir Solodov said fragments of the fuselage were found both on the shore and in the sea.
Officials said 22 passengers, including one child, were on board, as well as six crew members.
The head of the local administration in Palana, Olga Mokhireva, was among the passengers.
An investigation has been launched into the incident. Poor weather conditions are being considered as a possible cause.