Beijing (CNN) -- The death toll from earthquakes that rocked southwest China rose to 80 on Saturday, after the tremors destroyed roads and communication lines, and forced tens of thousands of evacuations, state media reported.
More than 800 others were injured in the Friday quakes, according to Xinhua news agency. Officials fear the death toll may rise as they scramble to reach affected areas.
Large rocks blocked roads, and communication lines and other infrastructure were downed, hampering rescue efforts.
About 100,000 people have been evacuated and 100,000 others are in need of relocation, state media reported.
Premier Wen Jiabao, who will direct rescue efforts, inspected stricken areas Saturday and visited the injured.
Initial estimates put the "direct economic losses" from the tremors at more than half a billion dollars, the news agency said.
The four earthquakes struck near the border of Yunnan and Guizhou provinces, the U.S. Geological Survey said. Their magnitudes ranged between 4.8 and 5.6, according to the U.S. agency.
All four quakes struck at a depth of 10 kilometers (six miles).
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.