A strong aftershock jolted southwestern China on Sunday, killing at least one person and rattling residents still reeling from the massive earthquake two weeks ago that killed more than 62,500.

The aftershock – the strongest to hit Sichuan province since the devastating May 12 quake – came as more foreign aid arrived in the disaster zone for the more than 5.4 million people left homeless by the tragedy.

Relief workers raced to reach those in need as conditions for survivors living in makeshift camps looked set to worsen, with rain falling throughout the day and forecasters saying heavy downpours were possible by nightfall.

State television quoted an earthquake relief official in the city of Guangyuan, north of the provincial capital Chengdu, as saying the aftershock caused at least one death and 262 injuries in that city.

No other reports of damage or casualties were immediately available.

The aftershock measured 6.4 on the Richter scale, an official with the Sichuan Earthquake Bureau told AFP – making it the strongest since the 8.0-magnitude quake on May 12 that destroyed large swathes of the province.

The US Geological Survey put the magnitude of Sunday's aftershock at 5.8.

The quake – which struck mid-afternoon and was centred about 250 kilometres (155 miles) northeast of Chengdu – sent people fleeing from buildings in the provincial capital, AFP correspondents witnessed.

"Houses started to shake and everybody went out into the street," Chengdu resident Lou Taiyi told AFP.

"We were thinking (May 12) was behind us but it is continuing," he said.

The death toll from the initial quake continued to rise, with the government putting the figure Sunday at 62,664, with another 23,775 missing.

Aid continued to pour into the region for the 5.47 million people left homeless and the more than 11 million people whom China says are expected to be housed in temporary camps as areas rendered unliveable are evacuated.

A Russian military transport plane carrying tents, blankets, field hospitals and other supplies touched down before dawn in Chengdu, state media reports said – one of 12 Russian aid flights expected.

A French medical team also arrived in Chengdu and headed for Guangyuan to help treat quake victims there, members told AFP.

The US Army has already flown in supplies and the German Red Cross has set up a field hospital in Dujiangyan.

China has praised the foreign help, which appears to have eased tensions with other countries that were sparked by criticism of Beijing's crackdown on anti-China demonstrations in Tibet in March.

During a visit to the devastated town of Yingxiu on Saturday, Premier Wen Jiabao told reporters he wanted to "sincerely thank the international community".

With hopes of finding more survivors all but extinguished, state media reported Sunday that an elderly man was freed unhurt from the collapsed remains of his home 11 days after the massive quake.

Xiao Zhihu, 80, had been given food and water by his wife since the quake hit, trapping him under a pillar, the official China News Service reported. He was freed on Friday.

Grief turned to anger for about two dozen parents of children killed in the quake, who staged a rare protest Sunday demanding a probe into whether shoddy school construction was to blame for the deaths of their children.

The parents, many of them clutching framed photos of their dead offspring, demonstrated on a highway leading out of the quake-devastated town of Mianzhu, an AFP correspondent witnessed.

"We are complaining about the shoddy quality of school buildings and we need justice from the government," 38-year-old Yang Fuyong, whose daughter died in the disaster, told AFP.

State media has said 9,000 teachers or schoolchildren were among the dead and missing. The government has vowed to investigate and punish anyone found responsible for substandard construction at schools.

Amid continuing efforts, rescue teams have admitted the search for survivors was over, with the focus now on clean-up and reconstruction operations.

In the town of Hanwang, now an expanse of rubble, a Dutch team of sniffer dogs combed through the crushed remains of the Hanwang People's Hospital for one woman who remained unaccounted for.

"I think we have a lot of work to do today, but it will be only finding dead bodies. I don't think there are any more survivors," Saad Attia, a member of the team