Russian air traffic controllers lost contact with an An-24 passenger plane carrying about 50 people in Russia's Far East on July 24.
The local Emergency Department said the missing plane was operated by the Siberia-based Angara airline.
The plane disappeared from radar screens en route to Tynda, an urban area in the Amur region bordering China.
Regional Governor Vasily Orlov said that according to preliminary data, there were 43 passengers, including 5 children and 6 crew members on the plane.
The search for the missing plane is underway. "All necessary forces and vehicles have been deployed to search for the plane," said Vasily Orlov.
Meanwhile, the emergency agency said there were about 40 people on the plane. TASS news agency quoted information from emergency response units as saying that the missing An-24 plane was carrying 46 people, including 40 passengers and 6 crew members.