A 6.6 magnitude earthquake in China's western Gansu province killed 22 people and seriously injured hundreds on Monday, state media said, adding that many homes in affected areas had collapsed.

The quake hit Minxian and Zhangxian counties, about 170 km (105 miles) southeast of the provincial capital of Lanzhou, at 7.45 on Monday morning (2345 GMT Sunday), the official Xinhua news agency said.

It put the number of people seriously injured at 296.

Eight towns in the remote, mountainous area sustained serious damage in the quake and subsequent flooding and mudslides, state media said.

There were also power outages and communications were cut off in 13 towns in Zhangxian County, Xinhua said.

A second 5.6 earthquake struck the same region about 90 minutes after the first, Xinhua said, the most significant of several aftershocks.

The United States Geological Survey said the first quake had a magnitude of 5.9.

Gansu abuts Sichuan province, where a 6.6 quake in April killed 164 people and injured more than 6,700, China's worst quake in three years.

That quake hit close to where a devastating 7.9 temblor killed some 70,000 people in May 2008. - Reuters