BEIJING (AP) _ Two earthquakes collapsed about 4,000 buildings in southwest China on Saturday, killing at least four people and injuring 220, officials said.

Yao'an County, in province of Yunnan, was first hit by a 6.0-magnitude quake that sent people scurrying out of their homes in the early morning.

About 1 1/2 hours later, the county was hit by an even stronger aftershock, of 6.5 magnitude, said a county seismologist who gave only his surname, Su.

Four people were killed, said a Yunnan government seismologist, surnamed Wu, without specifying how they died. Another 220 were injured and 4,000 buildings collapsed, said the State Seismology Bureau in Beijing.

The main compound of Yao'an's government headquarters was seriously damaged, and power in the area was cut, the state-run Xinhua News Agency said.

The authorities and media did not specify which tremor caused which damages and injuries.

In the town of Guantun, 18 miles from Yao'an, the early morning quakes woke tens of thousands of people and sent residents flocking into the streets, Xinhua said.

A strong tremor also was felt in the provincial capital Kunming, about 125 miles to the east of Yao'an, it said.

Yao'an was also hit by a 6.5-magnitude quake in 1962, and a 5.6-magnitude quake on August 14, 1993, Xinhua said.