A crowded bus fell into a deep gorge in northern India, killing at least 52 people, police there have said.

The driver lost control of the vehicle at a sharp bend on a mountain road in Himachal Pradesh state, nearly 620km north of New Delhi, said police officer Raj Kumar.

The bus then plunged more than 100m into the gorge, he said.

At least 20 other people injured in the accident have been hospitalised, the Press Trust of India news agency said.

Mr Kumar said the rescue operation was continuing and that the death toll of 52 was likely to rise.

Police figures show India has the world's highest road death toll, with more than 110,000 people dying each year in accidents commonly caused by overcrowding, speeding, and poor vehicle and road maintenance.