This woman lost her child when Juyuan Middle School collapsed
The shoddy construction of school buildings may be to blame for the high number of child casualties in China's earthquake, according to state media.
Tens of thousands of people have been buried in collapsed buildings following Monday's quake, many of them children.
The China Daily newspaper said questions needed to be raised about the structural quality of school buildings.
There have been frequent allegations of corruption in China's boom-fuelled construction industry.
China adopted strict building codes after more than 240,000 people died in an earthquake in Tangshan in the country's north-east in 1976. There few buildings had been built to withstand earthquakes, and thousands were destroyed.
But BBC correspondents in China say there is concern about corners being cut to siphon off money in the construction industry - especially in rural areas.
We cannot afford not to raise uneasy questions about the structural quality of school buildings
China Daily newspaper
In Dujiangyun hundreds of students are feared dead in the rubble of the Juyuan Middle School, where more than 50 bodies have been pulled out.
The school collapsed, but other nearby buildings withstood the earthquake.
One man told the AFP news agency: "I'll tell you why the school collapsed. It was shoddily built. Someone wanted to save money".
One mother told reporters there were doubts about the construction of the school.
''It was built in a very short time. They added one floor at a time, and continued building as they had money for it. So the base was not made for several floors. It was too weak."
"The whole building collapsed, straight down, hardly without shaking, even,'' she said.
Parents and grandparents mourn their children
And a newly-built primary school nearby also collapsed, leaving 100 children and teachers dead or missing.
Julian Bommer, Professor of Earthquake Risk Assessment at Imperial College, London told the BBC that the issue was one of enforcement.
"Countries in earthquake zones need rigorous inspection regimes to monitor the building regulations they introduce," he said
The state-run China Daily newspaper told readers in an editorial that if the school collapses were due to shoddy compliance with building codes the authorities should act with "firm resolve".
"We cannot afford not to raise uneasy questions about the structural quality of school buildings," it said.
The BBC's Dan Griffiths, in Sichuan, says that one effect of China's rapid economic growth is that some areas of the country have been thrown up with little regard for normal building codes.
And the grief of parents is all the greater, he says, because of China's one-child policy. "In some town's an entire generation may have been lost", he says.
The state news agency Xinhua reported that at least 1,000 students were dead or missing at the Beichuan Middle School in the city of Mianyang.
And at another school in Sichuan province's Qingchuan county where school children were taking a nap when the earthquake demolished a three-story building, 178 children were confirmed dead in the rubble and another 23 were missing, Xinhua said.
At least eight schools have been flattened in the earthquake. But it is unclear whether faulty design or poor construction was to blame for their collapse.
Some schools may have been built before current seismic codes were introduced.
The damage in rural areas is seen in sharp contrast to the relatively light effect of the earthquake on the city of Chengdu.
The city of 11 million people saw little physical damage and a death toll of several hundred. Construction standards on new buildings in the city are thought to have been more strictly enforced than in the countryside.
Regulations are great, but sometimes they can constitute a law without a police force
Professor Julian Bommer
Structural engineers say schools should always be be built to withstand higher stresses because of the vulnerability of children.
But Prof Bommer says the issue of enforcement is a challenge in all societies.
"Regulations are great, but sometimes they can constitute a law without a police force", he says.
"The other issue is that fresh regulations are not usually retrospective. So new buildings may be safe but the resources are not available to go back and strengthen existing structures which are still in use."
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