GILGIT: Up to 35 people, mainly soldiers, were killed when a bus skidded off a road and plunged into a river near a popular Pakistani tourist spot, police and a bus company official said Thursday.

The bus, which started its journey late Tuesday from Rawalpindi, a garrison city adjoining Islamabad, to the northern town of Skardu fell into the Indus river early Thursday, bus company manager Mohammad Hasan told AFP.

"There were 35 people on board and only the helper has survived after the bus fell into the Indus river at a place called Malopi," Hasan said.

"We have not found the wreckage of the bus yet and rescue teams have been sent to the crash site."

There were no phone links to the area and the company was facing difficulties in gathering details, Hasan added.

State television said that 34 people were killed.

Farman Ali, deputy police chief in the region, doubted there could be any survivors after the bus fell so far.

"All the passengers are dead and none of them could survive due to the fall from such a height," Ali told AFP.

He said there were some 30 to 35 passengers on board, including 27 soldiers, who were returning to their units from holiday.

Police joined local volunteers and other rescuers in a bid to retrieve the bodies from the turbulent waters, Ali added.

Most people travel by bus to Skardu, 290 kilometres (180 miles) northeast of the capital Islamabad. The state airline runs a daily flight between the cities, but the service is frequently disrupted by bad weather.

Pakistan has the world's third-highest death rate from traffic accidents, blamed on poor roads and reckless driving.

Skardu lies in high-altitude desert and is a starting point for mountaineers from all over the world who walk to the K-2 base camp.

Towering over the Karakoram range on uninhabited terrain between Pakistan and China, K2 is the second highest peak in the world after Nepal's Everest.

But mountaineers consider it more treacherous and more striking for its isolation and almost perfect pyramid shape.