The plane, operated by Sita Air, came down minutes after take-off from Kathmandu. Officials said it crashed into a river bank and caught fire.
Sixteen passengers and three crew were on board the twin-engine prop plane.
The UK Foreign Office says Britons are among the dead but has not confirmed how many.
Police and aviation officials, however, said that seven Britons, five Chinese nationals and seven Nepali nationals were on the plane, including the three Nepalese crew.
