At least 25 people were killed and 250 injured in an earthquake that struck a remote area of southwest China near the border with Myanmar on Thursday, state media reported.

The tremor reduced hundreds of houses to rubble, left some desperate residents trapped under buildings and triggered power cuts in the surrounding area of China, though no casualties were reported in Myanmar.

The epicentre of the 5.4-magnitude quake, which struck at 12:58 pm (0458 GMT), was located about 225 kilometres (140 miles) west-southwest of the ancient city of Dali in Yunnan province, the US Geological Survey reported.

The quake hit at a depth of 34 kilometres, the USGS said, though Chinese seismologists put the depth at just 10 kilometres.

The death toll had risen to 25, with 250 injured, 134 of them seriously, Xinhua news agency said, citing local authorities.

The quake toppled the homes of 1,039 families and seriously damaged nearly 5,000 others, mostly in the border town of Yingjiang, it said.

Witnesses told the news agency that parts of a supermarket and hotel had caved in, and that people were buried in the debris.

"The quake happened shortly after I finished my lunch. The house totally collapsed within only a few seconds," local reporter Miao Bin told Xinhua.

State television footage showed people on stretchers out on the streets, some hooked to drips, and survivors being pulled out of debris.

The quake triggered power outages in Yingjiang county, Xinhua said, adding that seven aftershocks had been recorded.

Nearly 1,000 soldiers have been sent to join the rescue operation, and authorities have dispatched thousands of tents, blankets, clothes and other items, it said.

In Myanmar, official sources said no casualties had been reported yet from the tremor.

A massive earthquake rocked the neighbouring province of Sichuan in May 2008, leaving nearly 87,000 people dead or missing.

earlier related report
Series of strong quakes rattles Japan
Tokyo (AFP) March 10, 2011 - A series of strong offshore earthquakes of above 6.0 magnitude shook Japan early on Thursday but there was no danger of a destructive tsunami, seismologists said.

The tremors follow a major 7.3 quake on Wednesday which swayed buildings in Tokyo and triggered a small tsunami but did not cause any casualties or property damage.

The latest was a 6.8-magnitude quake that hit at 6:24 am (2124 GMT Wednesday), 400 kilometres (250 miles) northeast of Tokyo at a shallow depth of nine kilometres below the Pacific seafloor, the Japan Meteorological Agency said.

The tremor prompted the agency to issue a tsunami warning which was soon lifted.

That came three hours after a 6.2-magnitude quake in the same region and another one measuring 6.1. Wednesday's quake and the early Thursday aftershocks were all in the same area.

There were no reports of major damage or casualties, local police said.

"We do not have to worry about a tsunami now but should be on alert for more aftershocks following yesterday's earthquake," an official at the Japanese agency said.

Around 20 percent of the world's most powerful earthquakes strike Japan, which sits on the "Ring of Fire" surrounding the Pacific Ocean.

Tectonics experts have warned of a 70 percent chance that the "Big One" -- a magnitude-seven earthquake or worse -- will strike the greater Tokyo region, home to around 35 million people, within the next 30 years.