General view of the capital of north-western China's Xinjiang region, Urumqi (AFP Photo/Philippe Lopez)

The epicentre was in Pishan county, 164 kilometres (102 miles) northwest of the city of Hotan and 131 kilometres southeast of Shache, known as Yarkand in Uighur, the language of the local mainly Muslim minority.

It was 20 kilometres deep according to USGS, which initially gave the magnitude as 6.1. A series of aftershocks followed with the strongest measuring 4.8, it said.

The area is on the edge of the Taklamakan desert, but the civil affairs ministry said six people had died.

The state news agency Xinhua said 48 people had been injured and cited officials saying an airport in Hotan had been closed.

Li Hua, a worker at a state-owned farm in Pishan, which has a population of 258,000, mainly Uighurs, told Xinhua that he felt the quake strongly, with his fourth-floor apartment shaking for about a minute.

"I'm feeling dizzy," it quoted Li as saying.

State broadcaster China Central Television showed footage of items falling off shelves in a local supermarket when the quake struck, and cracked walls at a fire station.

The government is sending 1,000 tents and disaster relief materials to the quake zone, the civil affairs ministry said.

The China Earthquake Network Centre gave the magnitude as 6.5.

China is regularly hit by earthquakes, particularly in its southwestern provinces of Sichuan and Yunnan.

Neighbouring Nepal, on the other side of the Himalayas, was hit by a devastating tremor in April which killed more than 8,800 people.

In May 2008, a 7.9 magnitude quake rocked Sichuan, killing more than 80,000 people and flattening swathes of the province in China's worst earthquake for more than three decades.

Last October, hundreds of people were injured and more than 100,000 displaced after a shallow 6.0 magnitude tremor hit Yunnan province, close to China's borders with Myanmar and Laos.

And last August, a 6.1-magnitude quake struck Yunnan, killing more than 600 people.