At least 31 people have been killed and 15 injured after a bus veered off a road in Nepal and plunged into a river.

The bus was travelling to the country's capital, Kathmandu, when it crashed into the Trishuli River, which is known for its fast currents.

Army rescuers and divers scoured the scene for bodies trapped in the wreckage, which was mostly submerged in the river, around 50 miles east of the capital.

"We have already pulled out 31 bodies, but we believe there could be more bodies trapped," a government official said, adding that it was not known how many people were on the bus when it crashed.

Shyam Prasad Bhandari continued that river currents were making it difficult for rescuers.

Mr Bhandari said a preliminary investigation showed that the bus was speeding along the two-lane mountain highway, which is the main route connecting Kathmandu with most other parts of the Himalayan nation.