Frantic efforts to reach remote mountain villages, cut off by landslides and still in dire need of help one week after the quake, were dealt another blow with the crash of one of the helicopters flying relief missions. "It's absolutely urgent right now to send tents to give people shelter. If nothing is done there will be thousands of deaths," said Thierry Velu, head of the French aid organisation Groupe de Secours Catastrophe Francais. Doctors across the devastated region said that survivors who have gone days without care for fractured bones were now succumbing to pneumonia, infections and gangrene that would force doctors to carry out amputations. And the World Health Organisation said that as well as the risk of infectious disease among survivors huddling together in unsanitary conditions, there was a grave risk of hypothermia as winter snows begin settling on mountain peaks. "In these conditions, people will freeze," WHO coordinator Altuf Musani said Saturday. "There is a small window of less than week to get to them. Those who are critically injured have very little chance." In the rugged Neelum Valley, Sean Keogh of Britain-based Medical Relief International also said that thousands of people there could also die in the next few days if help did not reach their isolated villages. "Their wounds have turned septic, they have fractures," he said Saturday after spending three days walking through villages cut off by landslides triggered in the October 8 quake which registered 7.6 on the Richter scale. "They are sheltering under sheets of iron. There's heavy rain, snow and it's very cold," he said. "A lot of survivors will die quite soon from their infections. We're seeing the first signs of gangrene." Helicopter pilots have said it was impossible to land in some areas where there were many injured people, forcing them to drop supplies and take off again despite the pleadings of people holding up injured children below. Others have made perilous touchdowns amid the piles of wreckage, to haul victims aboard and ferry them to hospitals in the capital Islamabad and other major cities. In the village of Jabori on the foothills of the mountains, the Pakistani army was distributing aid but villagers say what they sorely need is shelter. "We didn't have anything, no medicine, to care for the injured. We carried them down on stretchers to the hospital and then we waited," Mohammed Sabir, a bearded 60-year-old, said with resignation in the ruins of his house. "We need tents and food and they gave us mineral water," shouted Gul Mohammad, 24, who will go back empty-handed to his hamlet in the more remote mountains. Pakistan said Saturday that 38,000 people died in the disaster, raising the toll by 13,000 as bulldozers move into the wreckage and expose countless decomposing corpses. Another 3.3 million have been left homeless, and officials and aid agencies warn that many will not receive help before winter closes in on the rugged Himalayan region and leaves mountain villages completely stranded. Prime Minister Shaukat Aziz said that 58 choppers, including 18 from foreign countries, have joined the relief operation in the mountainous region where roads and communication links were snapped by the quake. But after delays Saturday when storms began drenching Kashmir and North West Frontier Province, airlifts were again halted for hours Sunday, and more rain was expected later in the day, the meteorological department said. The Pakistani military said it was unclear if the torrential rain was to blame for bringing down its Mi-17 chopper on Saturday near Bagh, one of the worst-hit towns, but that air crews had been flying up to 10 hours daily. "There were six people on board. They are all dead," spokesman Major General Shaukat Sultan said. "There is no rest for the pilots. This is our unprecedented relief operation." Balakot, which has been reduced to little more than an encampment of tents and flimsy shelters for traumatised victims, was turned into a bog after a night of rain. Hundreds of items of clothing that had been donated to survivors lay strewn on the ground, and there was no sign of the helicopters that have thundered overhead with cargoes of relief aid this week. Relief supplies have begun flowing into the bigger towns and cities in the quake zone, but the distribution system remains chaotic and the arrival of aid has often triggered fights among survivors.