SHANGHAI, Jun 4 -- A STRONG earthquake shook a hilly region in southwest China early yesterday, killing at least three people, injuring hundreds, forcing 120,000 people from their homes and damaging communications and power transmissions.

The 6.4-magnitude quake struck the county seat of Ning'er in Yunnan Province shortly after 5:30am.

Among the dead was a five-year-old boy who was crushed by debris. The boy's parents were also trapped but were rescued by local residents.

The quake affected 186,000 people in 35,000 households, many of whom moved to public areas as their homes collapsed or were damaged.

The local seismic bureau recorded more than 300 aftershocks by 3:30pm. The strongest occurred shortly before 11am, registering 5.1 on the Richter scale.

More than 70 mobile phone transmission stations were severely damaged, making cellular calls difficult.

The county's power grid was also severely damaged, and two mid-sized reservoirs were cracked.

Coal mines in Ning'er and surrounding areas were ordered to suspend operations, and workers were evacuated from underground, said Duan Liyuan, head of the provincial work safety bureau.

The government of Pu'er City has allocated one million yuan (US$131,000) for emergency relief. The provincial civil affairs department is sending 2,000 tents, 2,000 quilts and 2,000 articles of clothing to the stricken area.

The Ministry of Civil Affairs allotted 5,000 tents from the neighboring Guangxi Zhuang Autonomous Region.

The China Red Cross Society and its Yunnan branch sent a first batch of relief supplies worth 500,000 yuan, including tents, quilts, food and medicine.

In a statement issued by the Central Committee of Chinese Communist Party and the State Council, President Hu Jintao, Premier Wen Jiabao and Vice-Premier Hui Liangyu urged provincial government officials in Yunnan "to mobilize all resources available to treat the injured and minimize the loss of lives and property."

They also asked local authorities to closely monitor aftershocks and take good care of residents affected by the disaster.

A work group involving officials from the Ministry of Civil Affairs and several other government agencies arrived in the area last night.

Ning'er County, covering 3,670 square kilometers, has a population of 190,000.

Pu'er City, called "Simao" before it was renamed on April 8, is prone to strong earthquakes. It has experienced 20 tremors exceeding magnitude five since 1990.

Pu'er, in Yunnan's southwest, borders Vietnam, Laos and Myanmar, covers 45,000 square kilometers and has a population of 2.6 million.

Residents in Lincang City, about 200 kilometers from the epicenter, and the Dai Autonomous Prefecture of Xishuangbanna, 300 kilometers from the center, also felt the tremor.

(Xinhua)