"There have been no casualties, no-one killed or injured but over 3,100 houses have been damaged to soon extent, 700 to 800 seriously damaged," Mia Shouhua, director of the Delingha Seismological Bureau, told AFP.

He said "a handful" of houses had collapsed following the quake measuring 5.5 on the Richter scale that shook an area 70 kilometers (43 miles) outside Delingha city in western Qinghai province Tuesday.

"Thousands have been left homeless," he said.

The quake struck at 1:04 pm (0504 GMT), the State Seismological Bureau said.

The region, which lies some 500 kilometers (300 miles) north of the Tibetan capital Lhasa, is a sparsely populated area.

Mia said more than 10 aftershocks had been felt.

"The rescue effort is well under way," he said from the scene. "More than 800 tents have been transported to the area, which can accommodate at least 2,000 people.

In late March the region suffered two quakes measuring 5.8 and 6.3 on the Richter scale. No damage or casualties were reported afterwards.

TERRA.WIRE