BEIJING, May 30 - A shallow earthquake with a magnitude of 5.9 hit southwest China on Friday morning, the US Geological Survey said, with Chinese reports saying 29 people had been injured, five of them seriously.

The epicentre was in China's Yunnan province, 65 kilometres southeast of Myitkyina, capital of Kachin state in northern Myanmar, USGS said, estimating the quake's depth at 10 kilometres.

Shallow earthquakes can often cause greater damage than more powerful deep ones.

Chinese state media said the tremor hit Yingjiang county.

"Tremors were strongly felt in the county seat, where local residents rushed to open areas," the official Xinhua news agency said.

"Police have been sent to the township of Kachang, which is close to the epicentre," it added, citing local publicity officials.

Xinhua put the magnitude at 6.1, citing China's earthquake authorities.

Many people posting on Sina Weibo -- China's version of Twitter -- said the shaking lasted between six and eight seconds.

A picture posted online showed people in the centre of Mang, in Yingjiang county, standing in the street, with the poster saying they had run out of an eight-storey building because of the tremors.

USGS graded it as a seven on its "Shakemap" scale, saying that shaking would have been "very strong" and expecting "moderate" damage.

More than 50 relief workers have been sent to the region for "surveying, investigation and disaster evaluation", Xinhua said.

Southwest China lies where the Eurasian and Indian plates meet and is prone to earthquakes.

In May 2008, an 8.0-magnitude quake rocked Sichuan, which neighbours Yunnan, killing tens of thousands of people and flattening swathes of the province.

In September 2012, 80 people were killed when twin earthquakes struck the mountainous border area of Yunnan and Guizhou.

The two 5.6-magnitude quakes also left some 820 people injured and 201,000 displaced.

A month later 18 children were killed when their school was buried under a landslide triggered by sustained rains in the earthquake-hit area.

In March 2011, Yingjiang county was jolted by a 5.8-magnitude quake, leaving 26 people dead and more than 300 others injured. It was also hit by a 5.6 magnitude quake last Friday that injured at least 13 people.

Yingjiang had a population of 305,200 people at the end of 2010, according to official figures, 59.7 percent of them from 26 ethnic minority groups including Dai and Jingpo.