Relief teams were racing against time Saturday to rescue tens of thousands of stranded people in rain-ravaged northern India as the death toll from flash floods and landslides neared 600.

Rescuers have recovered scores of bodies from the swollen Ganges river with the government saying more than 30,000 people were still stranded after torrential monsoon rains struck the Himalayan state of Uttarakhand last week.

Raging rivers have swept away houses, buildings and entire villages, and destroyed bridges and narrow roads leading to pilgrimage towns in the mountainous state, which is known as the "Land of the Gods" for its revered Hindu shrines.

Home Minister Sushilkumar Shinde, who arrived in state capital Dehradun on Saturday, said 73,000 people had been rescued so far with up to 32,000 still stranded.

"At least 550 people have died and 392 people are injured," he told reporters, and urged authorities to complete the rescue work inside three days since fresh downpours were expected.

He also said steps were being taken up on a "war footing" to deal with the "national crisis".

Dozens of helicopters and thousands of soldiers have been deployed to rescue people trapped across the flood-devastated state.

TV images showed paratroopers rappelling from military choppers to assist in rescue operations.

The family of Kavita Tyagi, 26, stranded near the pilgrimage site of Badrinath for more than a week, recounted their ordeal after they were air-lifted by army choppers to Gauchar, a hill town in Chamoli district of the state.

"We had been stuck for more than a week. We ran out of food and all our money. My three-year-old son is with me and we can't describe the harrowing times that we have faced," she told AFP, her voice choked.

"My mother and brother are still to be evacuated since the chopper could accommodate only eight people. We are now just praying that they too land safely," Tyagi said.

Rescue teams were bracing for more challenges with further downpours expected in the state from Sunday onwards.

"The weather is already packing up. We are expecting fresh rains from tomorrow (Sunday) and that is why we are speeding up our operations," Priya Joshi, spokeswoman of the Indian Air Force, told AFP.

A group of 20 trekkers including six Americans were rescued Saturday after they were marooned near a remote glacier since the rains struck last week.

"They were on a trekking trip but got trapped because of the landslides and flash floods. The chopper has landed there now and they are all safe," Neeraj Khairwal, a top official of Pithoragarh district, told AFP.

Also Saturday, the army managed to make contact with nearly 1,000 people stuck in mountains near Kedarnath, the NDTV news network reported.

Distraught relatives clutching photographs of missing family members have been waiting for days outside Dehradun airport hoping for news of their loved ones.

The military operation, involving some 50 helicopters and more than 10,000 soldiers, was focused on reaching those stranded in the holy town of Badrinath after earlier finding widespread devastation in the Kedarnath temple area.

The Indian Air Force was transporting heavy equipment for repairs of roads and construction of temporary helipads, according to an official press release.

"A heavylift Mi-26 transport helicopter has already landed at Gauchar with 30 barrels of fuel and 70 paratroopers," it said.

Special trains and buses have been pressed into service to ferry tourists back home while medical and food supplies were also being flown in to the stranded people.

Minister Shinde said some of the bodies recovered from different places in the state were "badly mutilated", making it difficult to identify them.

"The DNA of the victims will be preserved," he said.

Uttarakhand Chief Minister Vijay Bahuguna had on Friday attacked the India Meteorological Department (IMD) for not issuing adequate warning ahead of the heavy rains, which struck earlier than expected, saying the local government was unable to prepare for the deluge and evacuate people on time.

"The IMD warning was not clear enough," he said.

Another 17 people have been killed in the adjacent state of Himachal Pradesh where seven foreigners were evacuated Saturday from the scenic tribal districts of Lahaul and Spiti.

Floods and landslides from monsoon rains have also struck neighbouring Nepal, leaving at least 39 people dead, the Nepalese government said.