BEIJING, Sept 7 (Reuters) - Two shallow 5.6 magnitude earthquakes hit mountainous southwestern China on Friday, killing at least 64 people and forcing tens of thousands of people from damaged buildings, state media said.
The quakes struck near the border of Yunnan and Guizhou provinces, the first one at 11:19 a.m. (0319 GMT) and the second one about 45 minutes later, the U.S. Geological Survey said.
About 700 people were injured and 20,000 homes damaged in the remote mountainous region about 350 km (210 miles) from the Yunnan provincial capital Kunming, the official Xinhua news agency said. As the number of dead climbed throughout the day, state media reported that Premier Wen Jiabao would travel to the area, as he has often done when disasters strike Chinese regions.
President Hu Jintao called for disaster relief to be dispatched to the area while attending the Asia-Pacific Economic Cooperation forum in the Russian city of Vladivostok.
Most of the victims were from Yiliang county in Yunnan, near the epicentre of the quakes, which struck at a depth of about 9 km (5.6 miles) according to the USGS.
By mid-afternoon, authorities had moved more than 100,000 from the area as a series of more than 60 aftershocks struck. No deaths were reported in Guizhou province.
Calls to police stations and hospitals in Yiliang went unanswered, but a worker at No. 2 Renmin Hospital in Zhaotong city said medical staff were busy treating the injured.
"We have admitted injured people, but don't have an overall number yet, and we can't comment without government approval," he told Reuters, declining to give his name.
Buildings in China's less developed regions are often thrown up with little regard for construction standards, making them susceptible to earthquakes.
Footage from state broadcaster CCTV showed boulder-covered roadways, abandoned cars and black smoke pouring from buildings.
"The hardest part of the rescue now is traffic. Roads are blocked and rescuers have to climb the mountains to reach hard-hit villages," Xinhua quoted Li Fuchun, an official from Luozehe, the town at the epicentre of the quake, as saying.
The death toll may rise as rescuers reach villages cut off by landslides, the news agency said.
Many structures in the area are built with mud and timber, making them more prone to collapse, the International Federation of Red Cross and Red Crescent Societies said.
"On the other hand, extricating people trapped in these structures may be easier than from under concrete/brick homes, meaning that there could be many more injuries proportionate to the number of deaths," it said.
In 2008, about 87,600 people were killed in the southwestern province of Sichuan when a 7.8 magnitude earthquake hit. Many of the victims died in the rubble of homes and schools built without adequate steel reinforcement.
A 6.9 magnitude earthquake in April 2010 killed nearly 3,000 people in a remote part of western Qinghai province, devastating much of Yushu county, where many displaced by the disaster still live in tents.
Quakes with an epicentre less than 70 km below the surface are considered shallow and can cause significant damage, even at lower magnitudes.
Christchurch, the largest city in New Zealand's South Island, is still recovering from a 5-km-deep quake measuring 6.3 which killed 182 people in February 2011.