The death toll from Chi na's most devastating earthquake in three decades has jumped to at least 11,921, a top disaster official said on Tuesday, as storms hampered rescuers in the most devastated areas. The state media reports indicated that the number of dead from the 7.9 magnitude quake was likely to soar. Xinhua news agency said 10,000 people were buried in the Mianzhu area of southwestern Sichuan province alone. Troops had also arrived for the first time at Wenchuan county, the epicentre of the quake. "The death toll from this disaster has already reached 11,921," Wang Zhenyao, disaster relief chief under the ministry of civil affairs, told reporters. "The first priority is to save people... as long as there is the slightest hope, we will try to save them," Mr Wang said, adding that the biggest threat to life was now mudslides. It was not immediately clear whether Mr Wang's toll was confined to Sichuan province. Hundreds more have perished in neighbouring provinces. A strong aftershock rocked Chengdu, capital of Sichuan, on Tuesday afternoon, one of more than 1,950 over the past day and keeping nervous residents on edge. "Office workers in downtown Chengdu took to the streets again after the quake," Xinhua said, adding it was thought to be the strongest since Monday's tremor. An official from China's seismological bureau official said more strong aftershocks could still hit Sichuan, Xinhua said. Hotels in Chengdu told guests to stay on lower floors. Heavy storms and wrecked roads hampered efforts to reach areas hardest-hit by China's worst earthquake in three decades on Tuesday. Premier Wen Jiabao, visiting Sichuan, ordered troops to clear roads to Wenchuan, a hilly area about 100 km from Chengdu. Damage from Monday's quake left the area, about 1,600 km southwest of Beijing, completely cut off. And rain and thick clouds over a province, famous for its giant panda reserves, meant that military helicopters sent to the area could not yet land. State television showed highways buckled and caved in from the quake and massive rockslides lining the roads. In Dujiangyan, about mid way between Chengdu and the epicentre, there was devastation, with buildings reduced to rubble and bodies on the streets. Troops and ambulances thronged the streets, and military trucks able to do heavy lifting had arrived. But many residents simply stood beside their wrecked homes, cradling possessions in their arms. Others huddled in relief tents under heavy rain. Rescuers had worked frantically through the night, pulling bodies from homes, schools, factories and hospitals demolished by the quake, which rolled from Sichuan across much of China and was felt as far away as Bangkok and Hanoi. In Dujiangyan, about 900 teenagers were buried under a collapsed three-storey school building. Premier Wen bowed three times in grief before some of the first 50 bodies pulled out, Xinhua reported. "Not one minute can be wasted," said Mr Wen, a trained geologist. "One minute, one second could mean a child's life." Relatives frantically tried to push past a line of soldiers surrounding the school, desperate for news of their children. "We're still pulling out people alive, but many, many have died," said one medical worker. At a second school in Dujiangyan, fewer than 100 of 420 students survived, Xinhua reported. The initial tremor was followed by a series of aftershocks, which shook the area through the night. "Some are still very strong," said a Dujiangyan resident. "We have put up tents outside to sleep in." A group of about 15 British tourists were out of reach near the epicentre, likely in Wolong a panda reserve whose phone lines were cut by the quake, Xinhua reported. China said that there had been no reports of foreign casualties as of midday. China's Communist Party leadership announced that coping with the quake's aftermath and ensuring that it did not threaten social stability were the government's priorities. But bloggers wondered about the quality of construction and why so many school buildings were reduced to rubble. Tibet's spiritual leader the Dalai Lama, accused by Beijing of involvement in deadly riots in the Tibetan capital in March, expressed his concern and offered his condolences to quake victims. Meanwhile, Chinese rescue workers have reported that 3,629 people had been confirmed dead and 18,645 were still buried under debris in Mianyang city, which neighbors the epicenter of the massive earthquake that struck China. The official Xinhua News Agency on Tuesday also quoted the rescue workers as saying there was serious damage to the buildings and roads in Mianyang and that water and gas supplies had been cut off.