KUNMING - More than 40,000 people have been affected by a 4.2-magnitude earthquake that hit Southwest China's Yunnan province on Tuesday morning, government authorities said.

No casualties have been reported since the quake occurred at 9:47 am, with the epicenter in Banhai Village, Ning'er Township of Ning'er County, said a spokesman with the county government.

Over 10,000 houses in four townships sustained minor damage, with fallen tiles and cracks in walls spotted, said the spokesman.

Two other quakes were also reported at 9:20 am and 11:47 am on Tuesday, with magnitudes of 2.5 and 3.8, respectively.

Disaster relief workers with the provincial civil affairs department have rushed to the quake zone.

Ning'er County is located in the city of Pu'er in the southern part of Yunnan. Ten earthquakes measuring over 5-magnitude have been recorded there to date. The strongest, a 6.4-magnitude quake, occurred on June 3, 2007, leaving three dead and nearly 300 injured.