Chinese President Hu Jintao led the nation in a minute's silence yesterday at the epicentre of the powerful Sichuan earthquake that flattened homes and communities one year ago.

At 2.28 pm the exact moment the disaster struck this southwest province, a grim-faced Mr Hu presided over the period of silence in the town of Yingxiu.

He and other leaders laid a white chrysanthemum - a symbol of mourning - at a commemorative wall in a ceremony broadcast live on state television.

Nearly 87,000 people died in the eight-magnitude earthquake or remain missing after a disaster that galvanised the nation but left deep emotional scars.

"Gradually, the reconstruction efforts have had important results, and the people in the disaster-hit areas are striding towards a new life," said Mr Hu in a speech after the Chinese flag was hoisted over the ruins of Yingxiu.

Life is slowly returning to normal as new homes, schools and factories are being built at a feverish rate at construction sites across this mountainous region, although entire communities have been relocated.

But in spite of all the efforts to move on, it remains an area of unmarked graves with nearly 18,000 people still listed as missing - presumably buried under the rubble of China's worst natural disaster in three decades.

"One year may be long enough for the most serious wounds to recover but not for broken hearts," the official China Daily said in an editorial.

Among the survivors, stories abound of lucky escapes.

Li Kaifu, a 40-year-old worker at the Hongda Chemical Factory, recalled he was at the doorway of the plant in Deyang city when the earthquake hit.

"When it started I thought for sure I was a goner," he said.

"I remember all the buildings started to crumble. All around me they were falling. My mind was racing, I panicked and ran outside. Everywhere buildings were collapsing. It was incredible."

In the city of Beichuan, the worst hit community, a ceremony was scheduled for a new middle school to replace one that collapsed, killing 1,000 students, the Global Times newspaper said.

For many survivors, notably parents, the most controversial aspect remains the way schools crumbled to the ground throughout the region - testimony to sloppy construction.

Hu Jianjun, a 27-year-old teacher in Dujiangyan, recalled desperate efforts to find survivors in the rubble of Sichuan Agricultural University, which was severely damaged.

"I remember the soldiers pulling out body after body. It was terrible," he said.

President Hu, accompanied by Vice Premier Li Keqiang and Foreign Minister Yang Jiechi, met foreign diplomats late on Monday who travelled to the disaster zone to pay their respects.

"The important thing we've learned," he said, "is that in the face of great natural disaster, the international community needs to intensify cooperation, join hands to overcome these difficult moments."

Hong Kong action film star Jackie Chan joined young quake survivors on Monday in singing "Nation", a song dedicated to the 60th anniversary of the founding of the communist state, state news agency Xinhua reported.

Amid all the attention, however, some survivors were just hoping for peace and quiet.

"I am 89 years old and I have never experienced anything like the quake. My house was completely destroyed, I lost everything I had," said Yuan Chuanzhen from her new home, a Red Cross-funded nursing facility in Mianzhu.

"I'm lucky, all eight of my children survived. Now they must look for jobs, so they can't take care of me. That's why I came here."