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 Yao'an county, a mountainous area of remote Yunnan province, told a foreign news agency one person had died and 328 had been injured. The US Geological Survey said the 5.7-magnitude quake struck at 7:19 pm (1719 PST) 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 Yao'an 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.