Around 1,000 people have been killed in flash floods and landslides in northern India, as heavy rains halted the search on Monday for thousands of tourists still stranded in the devastated Himalayan regions, officials said.

Indian priests were preparing to cremate hundreds of victims of the disaster even as 8,000 mainly pilgrims and tourists were still awaiting rescue nine days after flash floods and landslides hit the state of Uttarakhand.

"The official information with us is that about 1,000 people have died," Yashpal Arya, the disaster relief minister for Uttarakhand, told AFP.

Senior officials warned that the death toll could rise above 1,000 as flood waters recede and debris is cleared by emergency workers, showing the full extent of the disaster in the mountainous region, known as the "Land of the Gods" for its revered Hindu shrines.

Raging rivers have swept away houses, buildings and even entire villages in the state, which was packed with travellers in what is a peak tourist season. More than 1,000 bridges have been damaged along with roads, cutting off hard-hit villages and towns.

A doctor recounted a harrowing ordeal of walking with his family for 20 kilometres (12 miles) at night on a road strewn with bodies trapped under rocks from landslides to try to escape the devastation.

J.P. Semwal and his wife and two children trekked from the town of Kedarnath to another town from where they were airlifted to Dehradun.

"We followed the bodies that littered the route because we knew the bodies were of those who tried to escape earlier to safety," Semwal, 65, told AFP.

"There were landslides behind us as we walked in pitch darkness and finally reached Guptkashi. We were saved by the grace of God."

Preparations were under way for a mass cremation in the holy town of Kedarnath and elsewhere, with rescue workers ordered to collect tonnes of fire wood, amid concerns of an outbreak of disease from rotting bodies, officials said.

"The priests of temples have been requested to participate in the final rites," disaster management official K.N. Pandey told AFP.

Bad weather has grounded military helicopters, hampering the evacuation of people still stranded, many without food and water. Helicopters and thousands of soldiers have been deployed to help with the rescue efforts, with thousands of people already evacuated since the rains hit on June 15.

"We can only use the helicopters when the weather is clear. Rescue work can only resume when rains stop," said a senior army official in New Delhi.

Soldiers along with the Indo-Tibetan Border Police have been using harnesses and erecting rope bridges across flooded rivers as part of efforts to move people to safety.

A group of 14 Spanish mountaineers stuck for four nights in heavy snow at Kalindi Pass high in the Himalayas were reported to be among those rescued and airlifted to the state capital Dehradun.

The climbers were just below the pass at 5,946 metres (19,507 feet) when they were pinned down by snow, the Times of India said.

In some rare good news from the disaster area, an army medical team reached an isolated village in time to help deliver two babies on Sunday, the Press Trust of India (PTI) reported.

The team trekked almost 15 kilometres to reach Tijan village before assisting two pregnant women and calling for a helicopter to drop a female doctor into the area to help with the deliveries.

"The newborns and their mothers are in good health," Lieutenant General Vinod Bhatia said.

Fourteen stranded American tourists were evacuated on Monday as part of an air rescue operation in the adjacent state of Himachal Pradesh, where 20 people have been killed, PTI said.

Floods and landslides from monsoon rains have also struck neighbouring Nepal, leaving at least 39 people dead, according to the government in Kathmandu.

The monsoon, which covers the subcontinent from June to September, usually brings flooding. But the heavy rains arrived early this year, catching many by surprise and exposing a lack of preparedness.