At least 27 people have killed and 16 injured after a bus carrying dozens of Indian pilgrims crashed off a key road and crashed in Nepal, officials said.

The bus veered off Prithvi Highway and rolled towards a fast-flowing river.

Its roof was ripped open before it stopped on the rocky bank just short of the Marsyangdi’s rushing water.

Rescue workers recovered 27 bodies from the wreckage and flew the 16 injured to Kathmandu for treatment, according to Armed Police Force spokesperson Shailendra Thapa.

The wreckage was found near Abukhaireni, a town about 75 miles west of the capital.

It will be removed on Saturday as it is already dark and recovery will be difficult, police said.

There were 43 people on board the bus and all were Indian nationals, confirmed the Indian Embassy in Kathmandu.

The embassy said the bus fell about 500 feet from the road, and officials were co-ordinating with local authorities carrying out relief and rescue operations.

The bus from the neighbouring Indian town of Gorakhpur was heading towards Kathmandu from the resort town of Pokhara on Friday when it drove off the road midway through the journey.

Tens of thousands of Hindu pilgrims from neighbouring India visit Nepal every year to visit Hindu shrines. Nepal is a Hindu-majority country.

Local news reports said the pilgrims were also heading to Kathmandu to visit the Pashupatinath, the temple of Hindu god Shiva.

In July, two buses were swept away by landslides close to Friday’s accident site. Of the 65 people on board those two buses, only three survived and only about half the bodies were recovered.

The wreckage of the buses has not been found but authorities have continued to search.

The monsoon season that begins in June and last until September brings heavy rain to Nepal, triggering landslides and flooding.

The heavy rain also swells the rivers and adds speed to the generally fast-flowing rivers due to the mountainous terrain.

The season also turns rivers murky brown, making search missions difficult.

Rescuers used divers, scanners and even heavy magnets to try to locate the wreckage but no traces were found.

Bus accidents in Nepal are mostly due to poorly maintained roads and vehicles and much of the country is covered by mountains with narrow roads.