BEIJING -- A moderately strong earthquake struck southwestern China near the border with Myanmar on Friday, injuring at least 33 people.

Residents fled buildings and students evacuated schools that had already been damaged by a quake in the same area last week.

Five of the injured people were in serious condition, said a woman at the Yunnan provincial earthquake monitoring bureau, who gave only her surname, Xu.

The quake in Yunnan's Yingjiang county was registered at magnitude 6.1 by China's earthquake monitoring agency, but at 5.9 by the U.S. Geological Survey.

Electricity was cut to some areas in the quake zone, but communications were not affected.

More than 1,000 soldiers were helping rescue efforts and tents and bedding were sent to aid survivors. About 300,000 people live in the area.

A tremor lasting a few seconds was felt in Myitkyina, the capital of Myanmar's northeastern state of Kachin, and in the town of Bhamo, according to people reached there by phone. There were no reports of injuries or damage there.

China's mountainous southwest suffers frequent earthquakes. Last August, a quake in Yunnan killed five people.