Shimla, Aug 11 (IANS): At least 51 people, including 18 women, were killed and 46 others injured Saturday when an overcrowded bus rolled into a gorge in Chamba in Himachal Pradesh, police said.

The private bus was going to Chamba town when it skidded off the road and fell into the 300-feet deep gorge near Rajera, some 10 km from the town and around 475 km from the state capital.

"The 40-seater bus was overcrowded. People were even sitting on its roof," Chamba Deputy Commissioner Sunil Chaudhary told IANS.

He said 39 passengers died on the spot.

The injured have been admitted to hospitals in Chamba.

Witnesses said the bus was overcrowded and the driver probably lost control over the vehicle while negotiating a turn.

They said the administration had a tough time extricating the victims from the badly-damaged bus.

People in the area began rescue operations even before local authorities reached the spot.

Most of the victims were from Chamba district. The bus driver was among the dead.

Chief Minister Prem Kumar Dhumal and leader of opposition Vidya Stokes expressed grief over the accident.

The state government has initiated a magisterial probe into the accident.

But police blamed buses belonging to private operators and their "reckless, untrained drivers" for most of the fatal accidents in the state.

Chamba is one of remotest places in the state and scarcity and low frequency of passenger buses in the district leads to overcrowding of the vehicles.

The practice of travelling on the roof of the bus is prohibited but common in Himachal Pradesh, especially during religious festivals.

To prevent accidents, the government has banned use of mobile phones and music systems by drivers.