Two powerful earthquakes have struck south-west China, killing four people.

Officials in Yao'an, the epicentre of the two quakes, have warned that the casualty toll will be much heavier. Reports suggest at least 300 people have been injured.

The first quake, registering 5.9 on the Richter scale hit Yao'an at 0606 (2206 GMT on Friday). It was followed 90 minutes later by a 6.5-rated aftershock which caused many of the casualties, according to the regional seismology bureau.

Black-out

Lu Zhongnan, of Yao'an county civil affairs office told the AFP news agency: "At the present time we estimate between 7,000 and 8,000 homes have fallen down or been damaged.

"Several thousands will be sleeping outside tonight," he said.

Temperatures were expected to fall to about 0C on Saturday night, although day time temperatures had reached 18C, he said.

The quake caused a power black-out in the area, and strong tremors were also felt in the town of Kunming about 200km away.

Quake zone

Yao'an is in Yunnan province which lies along a geological fault susceptible to violent earthquakes.

The province was hit by two tremors in November last year, when three people were killed and 1,500 were injured in the city of Ninglang.

And in February 1996, a quake measuring seven on the Richter scale killed 228 and injured 3,700 in the city of Lijiang.

The worst quake to strike the region occurred in January 1970 when over 15,500 people were killed.

Seismology experts have been sent to the affected area and are expected to report back later on Saturday.