Kathmandu - At least 16 people were killed and nearly a dozen remained missing after a passenger bus plunged off a mountain highway, Nepalese police said Saturday.

The bus, on its way to the south-western town of Bharaihawa from the capital Kathmandu, reportedly fell about 100 metres off a highway into the swollen and fast-flowing Trishuli river early Saturday in Dhading district, about 50 kilometres west of the Nepalese capital.

Police said they had recovered 16 bodies but at least 12 people were still missing.

Another 24 passengers were injured and rushed to hospital, many with serious injuries.

Police said the driver lost control after hitting a pothole on a bridge and then smashed through the guardrail. Police believed the driver may have been speeding on the narrow mountain highway when the accident happened.

Rescuers were searching for the missing, but hopes of finding them alive were fast receding, police said. Rescuers battled raging currents on the river and bad weather conditions and were facing difficulties in the search operations.

Hundred of people are killed each year in road accidents involving public transport across Nepal.

Most accidents are blamed on reckless driving and poor road conditions made more dangerous by Nepal's mountainous terrain and disregard for passenger safety. (dpa)