A shallow 5.5-magnitude earthquake hit southwest China on Sunday, causing 700 homes to collapse and leaving 20 people injured, state media said.

The quake struck a rural area in the southwestern province of Yunnan on Sunday afternoon, damaging a further 2,500 houses, but there were no reported fatalities, according to state-run news agency Xinhua.

The quake's epicentre was just nine kilometres (5.6 miles) beneath the surface, Xinhua said.

Southwest China is prone to earthquakes, with twin quakes in Yunnan last September triggering landslides which killed at least 80 people.

The local earthquake bureau has dispatched a team to the area, Xinhua said.