BEIJING (AFP) - More than 400,000 people were being evacuated Friday after an earthquake hit southwest China, killing one person, injuring hundreds and flattening more than 18,000 homes, officials said. A government relief official in Yaoan county, a mountainous area of remote Yunnan province, told AFP one person had died and 328 had been injured. The US Geological Survey said the 5.7-magnitude quake struck at 7:19 pm (1119 GMT) Thursday at a shallow depth of 10 kilometres (6.2 miles) in Yunnan province. I was harvesting tobacco leaves... when the quake hit. I felt dizzy and saw villagers falling over. Many houses collapsed, Dong Zhaofu, a farmer in Yaoan county told the state-run Xinhua news agency. A 50-year-old woman was buried in the debris of collapsed houses and died later in hospital from serious blood loss, Xinhua said, citing local officials. The quake was centred on a relatively sparsely populated area 98 kilometres (61 miles) east-northeast of the tourist city of Dali. Several aftershocks followed, driving residents outdoors into the warm night for fear of greater damage, Xinhua said. The USGS reported a 5.0-magnitude aftershock just after 5 pm (0900 GMT) on Friday. More than 18,000 houses collapsed and over 75,000 others were damaged in six counties of Yunnan, with 30 people suffering serious injuries, according to Xinhua which cited local officials. Over 1,000 soldiers and policemen, including about 300 from neighbouring Sichuan province, were helping residents to safety, Xinhua said, adding that provincial authorities were sending tents, quilts and other aid supplies. It said more than 400,000 people in the quake zone needed to be evacuated or relocated. Yunnan governor Qin Guangrong ordered that 20 million yuan (2.9 million dollars) be allocated for disaster relief, the agency said. Emergency officials, however, estimate damage could cost the local economy 2.5 billion yuan, it reported. Last year in Sichuan, nearly 87,000 people were left dead or missing when a 8.0-magnitude earthquake shook the province in Chinas mountainous southwest. The deadliest earthquake to strike China in over 30 years flattened entire cities and towns, destroying schools, hospitals, homes, buildings and factories in nearly 50,000 villages. Yunnan province, where Thursday nights quake hit, lies on Chinas southern border with Laos, Myanmar and Vietnam. Yaoan county has a population of 207,900 from 23 separate ethnic groups, according to the county governments website. Its spectacular scenery and ethnic diversity have led Chinas government to promote the relatively unspoilt region as a tourist destination in recent years. Southwest China as a whole is part of the boundary between two of the Earths tectonic plates, the Indian and Asian plates, whose constant collision has created the Himalayan mountains and Tibetan plateau.