A bus carrying Indian tourists plunged off a Nepali highway and into a river on Friday, killing 27 people and injuring another 16. Deadly crashes are relatively common in the Himalayan republic as a result of poor roads, badly maintained vehicles and reckless driving.

The bus was travelling from the tourist city of Pokhara to the capital Kathmandu when the accident happened around noon in the central district of Tanahun.

"Out of 43, in total 27 people have died," Tanahun district official Janardan Gautam told AFP. Rescuers struggled against the raging Marsyangdi River to pull passengers out of the water. Another 16 injured passengers were airlifted by military helicopter to Kathmandu for treatment.

Authorities said that all the people who boarded the bus were Indian citizens who had stayed in Pokhara the night before and were heading to Kathmandu.

"Among the dead, 26 bodies are currently in a local hospital and will be sent to Pokhara after all proceedings," Gautam said.

One person died while undergoing treatment in Bharatpur hospital. "We were focused on the rescue today, we will now investigate the incident," Gautam added.

Nearly 2,400 people lost their lives on Nepal's roads in the 12 months to April, according to government figures. Friday's accident came a month after two buses with 59 passengers on board were swept into a river by a landslide in the nearby district of Chitwan.

Three people were able to escape alive from that incident, but authorities have so far only managed to recover 20 bodies in the weeks since, and the search is continuing for the two buses and the remains of the missing passengers. In January, 12 people were killed and 24 were injured when a bus heading to Kathmandu from Nepalgunj fell into a river.

Road travel becomes deadlier during the annual monsoon season as rains trigger landslides and floods across the mountainous nation. Floods, landslides and lightning strikes have killed over 170 people across the country since the monsoon began in June, according to the home ministry. Monsoon rains across South Asia from June to September offer respite from the summer heat and are crucial to replenishing water supplies, but also bring widespread death and destruction. Monsoon rainfall is hard to forecast and varies considerably, but scientists say climate change is making the season stronger and more erratic.