Beijing ( CNN ) -- The death toll may climb after a series of earthquakes in southwestern China killed at least 80 people and injured 731 , a state-run news agency reported Saturday . More than 6,600 homes were destroyed and about 430,000 damaged in Friday 's quakes , Xinhua said . 7.6-magnitude quake rattles Costa Rican coast . Premier Wen Jiabao inspected stricken areas early Saturday and visited the injured , the news agency reported . Wen will direct rescue operations . President Hu Jintao called for immediate relief efforts , according to China Central Television . Xinhua reported that 100,000 people have been evacuated and another 100,000 are in need of relocation . Initial estimates put the `` direct economic losses '' from the tremors at more than half a billion dollars , the news agency said . Xinhua described the mountainous area hit hard by the quakes as poverty-stricken . It said telecommunications and traffic infrastructure were seriously damaged . Four earthquakes struck near the border of the provinces of Yunnan and Guizhou between 11:19 a.m. and 1:12 p.m. local time , the U.S. Geological Survey said . Their magnitudes ranged between 4.8 and 5.6 , according to the U.S. agency . Strong offshore quake kills 1 in the Philippines . The first quake took place near the border between Yiliang County in Yunnan and Weining County in Guizhou , Xinhua said . All four quakes struck at a depth of about 10 kilometers ( six miles ) , the USGS said . The southwestern region of China is prone to earthquakes . In May 2008 , a magnitude 7.9 quake in Sichuan province caused widespread devastation , killing at least 69,000 people . CNN 's Steven Jiang contributed to this report .
Chinese Premier Wen Jiabao visits stricken areas . The U.S. and China have been at odds over the South China Sea for years. Their magnitudes range between 4.8 and 5.6 , the U.S. Geological Survey says . More than 430,000 houses are damaged and 6,600 destroyed , state media reports .