Parents who lost children in the powerful earthquake that struck southwest China May 12 have marked International Children's Day with grief and anger at perceived corruption. Meanwhile, the death toll from the quake is near 69,000, with the numbers expected to continue rising. Stephanie Ho reports from Beijing.

For many Chinese people, the most unbearable image of the devastation was the thousands of dead children, who died when the earthquake crumpled their schools.

These deaths have prompted suspicions among many parents that the building standards for the schools may been ignored because of corruption.

In the town of Juyuan, about 100 grieving parents met at their children's' collapsed middle school, to mark International Children's Day Sunday. A large white banner hung on a part of the school that was still standing, calling for a "blood debt" to be paid by those school or local officials responsible for the allegedly shoddy construction. About 900 students were buried in the school.

The state-run Xinhua news agency says the Chinese government has ordered appraisals of all school buildings in the quake zone. It quoted a Construction Ministry investigator as saying that steel rods used to reinforce the concrete at the Juyuan Middle School were too thin.

Although the earthquake's epicenter was in southwest Sichuan province, rumbles were felt as far away as Beijing, 1,500 kilometers to the north, and other parts of China also experienced some damage.

Chinese President Hu Jintao on Saturday traveled to northwestern China's Shaanxi Province to oversee quake relief operations there. He also marked Children's Day as he spoke to a group of primary school students in a tent school.

Mr. Hu urged the children to have confidence that the Communist Party and the Chinese government will rebuild their schools and give them a better learning environment.

In other quake related news, official Chinese media say a Chinese military helicopter carrying out relief work has crashed amid fog and strong turbulence. There are no reports of casualties, although there were 14 people on board.

Xinhua says the military has completed a project to drain backed-up water at the swelling Tangjiashan Lake, which is threatening more than a million people following the quake.

Nearly 200,000 people have been evacuated from the area and more than a million others could be moved to higher ground if the lake overflows. The new lake is one of more than 30 created when landslides triggered by the earthquake and its aftershocks blocked rivers.