At least 13 people were injured and thousands of structures damaged when a 5.6-magnitude earthquake jolted a county in southwest China, bordering Myanmar, officials said.

The quake shook Yingjiang County of Yunnan Province yesterday, affecting 13,000 residents in 15 towns and toppled and damaged 9,688 houses, the officials said.

The epicentre was in Kachang Town of Yingjiang, which is on a quake-prone belt. The epicentre was measured at a depth of 12 km, the China Earthquake Networks Center said.

The quake has also damaged 36 schools and 9 bridges. More than 10,000 people have been relocated, state-run Xinhua news agency reported.

Of the total injured, ten are receiving treatment, while three have left the hospital.

About 3,000 rescuers are working in the county to remove potential risks, set up tents and resume the power supply. Cracks have been seen in the building of Wupai Primary School in Kachang Town.

There had been 293 aftershocks by 3 p.m., according to Wei Gang, head of the county government.

Residents rushed out of their homes when the quake happened. Tiles fell from some roofs and there was a power blackout in the epicentre, said Tao Jiqing, Party secretary of the county.

The provincial seismological bureau has dispatched a work team of 50 people to the region to carry out surveying, investigation and disaster evaluation work.

The Yunnan Provincial Civil Affairs Department has sent 4,000 tents, 2,000 quilts and 2,000 folding beds to the quake-hit areas.