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China marks the first anniversary of a devastating earthquake that left nearly 90,000 people dead or missing and 5 million homeless. State leaders laid flowers and survivors burned paper money for departed spirits.

Addressing a memorial service before a destroyed school in the Sichuan province town of Yingxiu, President Hu Jintao pledged strengthened support for rebuilding and disaster prevention and efforts toward a "more harmonious relationship between man and nature."

"The great task of earthquake rescue and recovery reminds us again that unity is strength, that victory can only be gained through struggle," said Hu, before leading military and civilian leaders, diplomats, students and emergency services workers in laying carnations before a stone memorial.

The 30-minute ceremony followed a minute of silence beginning at 2:28 p.m. (0628 GMT), the moment the magnitude-7.9 temblor — the deadliest earthquake to hit China in decades — struck on May 12, 2008, toppling or burying villages, snapping bridges and razing large portions of Sichuan and two neighboring provinces.

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The solemn event was broadcast live on national television, underscoring the disaster's searing effect on the national consciousness.

In the nearby county seat of Beichuan, mourners gathered at a destroyed middle school where about 1,000 students and faculty were killed, piling flowers and burning candles and sticks of incense amid the smoke and crackle of exploding firecrackers. Many brought pictures of their dead children and pasted notes to a metal fence surrounding the rubble, including one reading "peace to the dead, strength to the living."

Burning paper money as an offering to their 17-year-old son who was crushed in the school collapse, Jin Dalan and her husband Chen Guanghui gave voice both to their bereavement and continuing resentment over the government's treatment of parents.

"I'm just trying to talk to him to ask why he doesn't visit me in my dreams. I just want to know that he's OK and that no one is bullying him,' said Jin, 45.

Chen, like many parents of dead students, said he was still waiting for a proper response to allegations that schools were inherently unsafe as a result of shoddy construction enabled by corruption and weak oversight.

"Of course I'm angry. The school was badly built. Nothing else around here collapsed," Chen, 47, said.

More than a dozen police officers kept watch over the increasingly agitated parents, who shouted abuse at them when a plainclothes officer tried to break up an interview with an Associated Press reporter.

Traffic was heavy on narrow roads leading into the deep mountains that surround Beichuan, the closest major town to the epicenter of the quake. Police blocked roads about 5 kilometers (3 miles) from the heart of the old town, leaving hundreds of former residents to stream into the mountains on foot, many heading out before dawn.

Last year's destruction triggered an outpouring of grief around China and united the country in a massive rescue effort boosted by volunteers, private donations, and international aid.

The quake cast a shadow over the Beijing Summer Olympics that followed in August, and while Chinese media have continued to report on developments in the quake zones, new concerns have since begun to compete for attention.

Although the government continues to fund reconstruction, the devastation to the local economy accompanied by the global economic crisis has cast doubts on whether the remote region will ever fully recover. In the days leading up to the anniversary, the nation struggled with the worldwide outbreak of swine flu, with China's first case officially confirmed in Sichuan's provincial capital of Chengdu on Monday.

The most politically incendiary issue, however, remains the issue of school safety amid allegations that corruption and mismanagement led to shoddy construction.

Parents have tried to sue or petition local and central authorities, but many have been detained or warned against speaking out. Activists and lawyers who have tried to help them have met the same fate and reporters visiting the area have been detained, harassed, and physically threatened.

So volatile is the issue that until last week, the government had refused to release an official tally of students who died, saying the task was complicated and time-consuming. That figure, released in an apparent response to public pressure, showed 5,335 students were killed in the quake— although parents and activists say the number is too low.

So far, no one has been punished or held responsible over the schools, and officials insist that they have not found evidence so far of shoddy construction — a claim questioned by experts and parents alike.

Xu Changyun, a 39-year-old construction worker who also lost his son at the Beichuan school, said parents were losing hope of ever finding justice.

"I've lost all the hope deep inside, and I don't think our effort will have any effect," Xu said.