KUNMING, Aug. 17 -- At least six people were injured after an earthquake measuring 5.0 on the Richter scale jolted Yongshan County of southwest China's Yunnan Province at 6:07 a.m. on Sunday, local authorities said.

The epicenter was in Wuji Township, 21 kilometers away from the county seat. The source of the quake was 7 km deep.

The quake was strongly felt in the neighboring counties of Suijiang, Daguan and Zhenxiong as well as the Zhaoyang District of Zhaotong City, which administers Yongshan, according to the provincial seismological bureau.

Six people in Yongshan were injured and 337 houses were damaged as of 9 a.m.. Cracks have been seen in adobe houses and more than 10 cattle lots collapsed at Jinping Village, according to the county government.

Damages of roads, tunnels and power transmission lines were reported in five townships. More than 1,000 local officials, policemen and militia are working at affected regions for rescue and disaster investigation.

About 200 firefighters from various cities are heading to Yongshan for rescue.

Civil affairs authorities have sent 200 tents, 2,000 quilts and 2,000 overcoats to the county.

Twenty-two aftershocks had been reported as of 8 a.m. on Sunday.Communication in the county is unimpeded, according to the seismological bureau.

Yunnan governor Li Jiheng is leading a work team to Yongshan from Ludian, a county also in Zhaotong City where a 6.5-magnitude earthquake on Aug. 3 killed more than 600 people and destroyed 80,000 homes.

The Yongshan earthquake is not an aftershock of the Ludian earthquake as the epicenters of the two quakes are 113 km away from each other, said Zhang Junwei, an official with the provincial seismological bureau.