Kathmandu - At least 14 people were killed and dozens of others injured Friday morning when a passenger bus fell into a swollen river after veering off a mountain highway, police said.

The bus plunged about 150 metres off the road at Mahadevbesi of Dhading district, about 70 kilometres west of the Nepalese capital Kathmandu, and plunged into the fast-flowing Trishuli River.

Most of the victims, which included two Indian nationals, died before rescuers could reach the area. Police said another 38 people were injured and rushed to hospital. Many are in serious condition.

Police said many of the victims died when they were trapped inside the mangled wreckage of the bus.

The bus was on its way to Kathmandu from the southern city of Birgunj when the accident occurred.

The cause of the accident was not immediately known.

However, police suspected speeding may have resulted in the driver losing control of the vehicle on the narrow winding mountain highway.

Police said the bus was carrying 52 people and was not overcrowded.

Hundreds of people are killed each year in road accidents in Nepal, blamed mostly on careless driving.

Driving in Nepal is especially dangerous during monsoon season lasting from June to the end of September when heavy rains cause frequent landslides that damage or wash away portions of roads in the mountains. (dpa)