Rescue teams toiled in pouring rain on Thursday in the debris left by last week's devastating earthquake in Nepal, but officials said the chances of finding any more survivors was bleak as the death toll neared 5,500.

While rescue teams were out in the capital Kathmandu despite the rain, helicopters could not fly to the worst-hit areas in the countryside of the impoverished Himalayan nation.

"There may not be any more survivors," said Rameshwor Dandal, chief of the disaster management centre at Nepal's home ministry. "The rain is adding to the problems. Nature seems to be against us."

Anger over the slow pace of the rescue flared on Wednesday with protests outside parliament. In the interior, villagers blocked trucks carrying supplies, demanding the government do more to hasten the distribution of aid that has flooded into the country but has been slow to reach those in need.

An official from Nepal's home ministry said the number of confirmed deaths from Saturday's 7.8 magnitude earthquake had risen to 5,489 by Thursday morning. Almost 11,000 were injured, and more than 80 were also killed in neighbouring India and Tibet.

Many people have been sleeping in the open after the quake - the United Nations has said 600,000 houses were destroyed or damaged. It has said eight million people have been affected, with at least two million in need of tents, water, food and medicines over the next three months.

Dandal said foreign rescue teams had told him that their work is almost done because there is little chance of finding any survivors.

A Nepali-French rescue team pulled a 28-year-old man, Rishi Khanal, from a collapsed apartment block in Kathmandu on Tuesday after he had spent around 80 hours trapped in a room with three dead bodies.

However, doctors amputated one of his legs on Wednesday because of damage from prolonged internal bleeding.

Nepal is appealing to foreign governments for more helicopters. There are currently about 20 Nepali army, private and Indian army helicopters involved in rescue operations, according to Laxmi Prasad Dhakal, a home ministry official. China is expected to send helicopters on Thursday, he said.

Prime Minister Sushil Koirala has told Reuters the death toll could reach 10,000, with information on casualties and damage from far-flung villages and towns yet to come in.

That would surpass the 8,500 who died in a 1934 earthquake, the last disaster on this scale to hit the nation of 28 million people sandwiched between India and China.

WORRY OF DISEASE

In Kathmandu and other cities, hospitals quickly overflowed with injured soon after the quake, with many being treated out in the open or not at all.

Guna Raj, who works for a Kathmandu-based NGO specialising in providing sanitation, said there have been outbreaks of diarrhoea in relief camps because of a shortage of toilets and clean water.

"In the next few days or weeks I am sure there will be an outbreak of epidemics," said Raj, who is involved in the relief effort.

Tensions between foreigners and Nepalis desperate for relief surfaced, rescuers said, as fresh avalanches were reported in several areas.

Members of Israeli search-and-rescue group Magnus said hundreds of tourists, including about 100 Israelis, were airlifted out of Langtang in Rasuwa district, a popular trekking area north of Kathmandu hit by an avalanche on Tuesday. But at least two foreigners, whose nationalities were as yet unknown, were found dead, the home ministry said.

Fights had broken out there because of food shortages, Magnus team member Amit Rubin said. One of the trekkers said there had also been scuffles over places on the rescue helicopters.

The quake also triggered an avalanche on Mount Everest that killed at least 18 climbers and guides, including four foreigners, the worst disaster on the world's highest peak. – Reuters