A major earthquake of 7.8 magnitude ripped through southwest China on Monday afternoon, killing more than 8,700 people and sending shock waves through cities across a large swathe of the country and southeast Asia. The epicentre of the quake was pinpointed at Wenchuan County, some 100 km northwest of Chengdu, the capital of Sichuan province and home to over 12 million people. Xinhua reported from Chengdu, quoting local authorities, that the death toll in Sichuan Province has climbed to 8,533. Sources with the temporary headquarters for disaster relief headed by Premier Wen Jiabao in Sichuan said casualties are being tallied in other areas affected by the massive quake. The death toll could rise dramatically as contact is being made with regions cut off by the disaster. Xinhua said authorities are yet to reach Wenchuan County, which sits at the epicentre of the earthquake with a population of about 1,12,000. The agency reported local government sources as saying that between 3000-5,000 people were feared dead in one Sichuan county, Beichuan, alone. Nine hundred teenagers were also reported buried when their high school located in Sichuan's Dujiangyan city, about 100 km from Wenchuan, crumbled. Rescuers had recovered at least 50 bodies from the debris of the three-storey building by late Monday night. The earthquake struck just before 2.30 p.m. Smaller quakes were felt a few minutes later in several other parts of the country as far away as Beijing in the northeast and Shanghai in the southeast. Telecom networks in the areas near the epicentre, including Chengdu and Chongqing, were disrupted. In Beijing, aftershocks led to several hundred citizens running out of high-rise buildings onto the streets, although no major damage or injuries were reported. Similar scenes of panic were played out in Vietnam, Hanoi and Bangkok, 3,300 km to the south of the epicentre. However, China's mammoth Three Gorges Dam, which is located near the quake's impact area, survived the impact. Troops were ordered to help with the disaster relief work.