The earthquake near Dingxi city had a magnitude of 5.98 and was shallow, with a depth of just 9.8 km (6 miles), according to the US Geological Survey.

Dingxi local authorities say many houses have collapsed in the quake.

In 2008, an earthquake in Sichuan province left up to 90,000 people dead and millions homeless.

At least 47 people had been killed, reports from China's national radio and Agence-France Presse news agency citing local officials said.

Another 296 other people were injured, the Dingxi local government said on its official Sina Weibo microblog.

In Gansu's Zhangxian county, at least 5,600 houses were seriously damaged and 380 collapsed, while some areas suffered from power cuts or mobile communications being disrupted, the Earthquake Administration of Gansu province said.

Crews of fire fighters and rescue dogs have already arrived at the scene, the BBC's Celia Hatton in Beijing reports.

The closer to the surface an earthquake strikes, the more damage it can cause, our correspondent adds.

The earthquake reportedly triggered a series of mudslides and landslides, state-run news agency Xinhua reported.

The Gansu military police has deployed 500 soldiers, including 120 specialist rescuers, while 500 emergency tents and 2,000 quilts are also being transported to affected areas, Xinhua added.

Officials from the civil affairs, transportation and earthquake departments are also visiting local towns to assess the damage, a statement on the Dingxi party website said.

"You could see the chandeliers wobble and the windows vibrating and making noise, but there aren't any cracks in the walls," AFP quoted a clerk at Wuyang Hotel, about 40 km (25 miles) from the epicentre, as saying.

"Shop assistants all poured out onto the streets when the shaking began," the clerk said.