Villagers camped outdoors and hospitals were jammed Wednesday after a strong earthquake shook China's southwest, killing up to three people and injuring as many as 600, officials and state media said.

Some 92 aftershocks have been felt since the magnitude-5.6 quake struck Ludian County (search) in earthquake-prone Yunnan province (search) Tuesday evening, a county official, Shi Zaiqing, said by telephone.

State television had reported that five people were killed, but gave the figure as three in a later broadcast. It did not explain the change.

Shi put the death toll at two and said 422 people were injured when the quake rolled. He said residents were evacuated but could not give an exact figure or the extent of damage.

The area's three hospitals "all were packed with injured people," he said.

The quake Tuesday caused 5,175 houses to collapse and damaged thousands more, according to a statement on the county government's Web site.

By Wednesday afternoon, the official Xinhua News Agency put the casualties at 600, with 142 injured seriously. The report cited Deng Xianpei, mayor of Zhaotong, a city where one person was killed.

Residents were living in tents or sleeping outdoors, but summer temperatures were comfortable and supplies of drinking water and food were adequate, Shi said.

"We are very, very busy right now," he said before hanging up abruptly.

In its noon newscast, China Central Television showed huge piles of rubble and partially collapsed brick buildings at the earthquake site. Scores of people, some with bandages around their heads, were crammed into a room apparently serving as a makeshift shelter. Some slept on the floor while others sat on thin mattresses.

Ludian county, with about 370,000 people, is one of China's poorest areas.

The quake's epicenter was 160 miles north of Kunming, the provincial capital, Xinhua said.

In November, two quakes measuring magnitude-5.1 and 5.0 rocked the Ludian area, killing four people and injuring 120.