India's military battled on Thursday to reach villages and towns cut off by flash floods and landslides in the country's north as officials warned at least 1,000 people may have been killed.

Helicopters and close to 10,000 soldiers have been deployed to rescue tourists and pilgrims stranded after floods caused by torrential monsoon rains hit the Himalayan state of Uttarakhand at the weekend.

More than 22,400 people have so far been rescued, as the military takes advantage of clearer weather, but another 62,000 are still stranded, the Home Ministry said in a statement.

"Our priority is to take out the children and women first by helicopter," said Ajay Chadha, chief of the Indo-Tibetan Border Police.

"We hope to rescue all the living and then start the scavenging task," Chadha said in New Delhi, referring to the task of finding the dead.

Houses, buildings and vehicles have collapsed or been swept away by overflowing rivers and landslides, while bridges and narrow roads leading to pilgrimage towns have also been destroyed, officials said.

Torrential rains four and a half times as heavy as usual have hit Uttarakhand, known as the "Land of the Gods", where Hindu shrines and temples built high in the mountains attract many pilgrims.

"There are some 3,000 of us stuck in Gangotri (a pilgrimage site) for the past few days and there is no food, no drinking water or assurances from the government," a pilgrim, Parwinder Singh, told CNN-IBN by telephone.

"It is very difficult to move from here," he added.

At least 138 people have been killed across Uttarakhand and two neighbouring states also hit by floods and landslides, officials said, but shrine authorities warned the toll was more than 1,000.

"We estimate more than 1,000 people have died as unattended bodies are scattered all around," said Ganesh Godiyal, chairman of a trust in charge of several shrines in the pilgrimage towns of Kedarnath and Badrinath.

Over the border in Nepal, floods and landslides also triggered by the monsoon have left at least 39 people dead mostly in remote parts of the country, officials said.

The military operation was concentrating on reaching the worst-hit Kedarnath temple area, as families of the missing faced an anxious wait in Uttarakhand capital's Dehradun.

Some of those rescued told of scrambling to higher ground to escape raging waters, only to watch helplessly as below them buildings, cars and even dead bodies were swept away.

"There is nothing left in Kedarnath now except the temple," pilgrim Sitaram Sukhatiahe told the Press Trust of India after arriving by helicopter in Dehradun.

"It was shocking to watch a place bustling with people metamorphose in a matter of a few hours into an island of death and destruction," he said.

One of those stranded was Indian cricket star Harbhajan Singh, who was attempting to reach a Sikh pilgrimage site but had to take refuge in a police station.

"Some people are saying that we're stuck but I wouldn't say that we're stuck, I'd say we've been saved by God," said the spin bowler, who was later flown out of the flood-hit area by military chopper.

"With the kind of rainstorm we witnessed, anything could have happened. Many people lost their lives," the cricketer said.

Figures for the death toll have varied considerably, underscoring the difficulty of reaching isolated areas. An Uttarakhand state lawmaker, Shaila Rani Rawat, put the death toll at 2,000, but disaster management officials could not confirm this.

Nearly 10,000 soldiers along with 13 teams from the National Disaster Response Force have been deployed for the rescue and relief effort, the government said.

Indian paramilitary officers have been building rope and log bridges across raging rivers to try to reach those stranded.

Relief camps have been set up to house evacuated residents and tourists. Some 22 helicopters are ferrying many of those rescued to the camps, while 14 tonnes of food and relief aid has been dropped in remote areas, the air force and the government said.

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

Landslides and floods in Nepal kill 39
Kathmandu (AFP) June 20, 2013 - At least 39 people have been killed in landslides and floods triggered by heavy monsoon rain in mainly remote parts of Nepal, a government official said Thursday.

"So far, 39 people from across the country have been killed by landslides and floods," said Laxmi Prasad Dhakal, chief of National Emergency Operation Centre, which monitors natural disasters in Nepal.

The death toll is likely to rise, with some 18 people still missing, after floods hit mostly farming communities in the country's southern plains and remote western hills, said Dhakal.

"The death toll is likely to increase as the areas affected are remote and we are still gathering information," Dhakal said.

Fourteen out of the country's 75 districts have been declared disaster-hit by the government following the floods which have also damaged more than 180 homes, officials said.

The head of the government, former chief justice Khil Raj Regmi, visited the worst-hit Darchula district on Thursday, where more than 100 homes have been damaged by a flooding river.

The government has decided to deliver a relief package of 40,000 rupees ($420) each to the victims. On Wednesday, a helicopter carrying blankets and medicines was sent to the disaster-hit region.

Hundreds of people die every year from flooding and landslides during the monsoon season in Nepal.

The annual monsoon has also struck over the border in India, with landslides and floods leaving hundreds dead and thousands more people stranded.