Feng Li, Getty Images
Earthquake survivors wash clothes by their tents Wednesday in Sichuan province. Many sleep outdoors because of damaged homes or fear of aftershocks.

MIANYANG, China — As China marked Thursday's one-month anniversary of its deadly earthquake, some weary survivors were once again on the move, setting up tents and shelters on city sidewalks away from a threatened flood.

Soldiers in Mianyang, the largest urban area directly under threat from the Tangjiashan quake-formed lake, helped survivors move their belongings yet again while vehicles drove by loaded with plastic stools and bottled water.

Cutting through the city, the Fu River was running high and fast, and life remained far from normal. Many residents continue to sleep outdoors because of damaged homes or fear of aftershocks from the May 12 disaster that jolted Sichuan province and neighboring regions. Many businesses were closed, some with sandbags stacked at their entrances.

Although they remained homeless, residents said conditions near their former dwellings were far superior to those in the hastily erected camps in the hills where some had been living for almost two weeks because of flood fears.

"Life wasn't so good up there. When it rained, the water didn't drain and sometimes it reached up to our ankles," said street sweeper Zhao Shuping, 46, who sought shelter on higher ground on June 2.

Authorities had evacuated 250,000 people near the lake, which formed when landslides blocked a river above the destroyed town of Beichuan. It was the largest of 30 lakes created by the quake.

In Beijing, China showcased its massive aid effort, with soldiers, medical workers and politicians gathering in the Great Hall of the People on Wednesday to hear emotional testimonials about its success.

The nationally televised event featured heroes from the quake — a teacher from devastated Beichuan, a volunteer nurse from southern Guangdong, a military commander who led troops on a 31-hour march to reach the epicenter.

Organized by the Communist Party's propaganda department, it underscored the government's emphasis on positive coverage amid a long and daunting recovery effort. Nearly 70,000 people died in the disaster, with another 17,000 missing after the 7.9-magnitude quake.

In the first days after the quake, China's typically harsh media restrictions were relaxed, allowing both domestic and foreign reporters unusual freedom in covering the disaster. But in recent weeks, the government has begun rolling back liberties as hard questions have continued about corruption and shoddy construction of schools.

Such measures were apparent Thursday as security forces cordoned off destroyed schools, apparently on alert for protests by parents demanding investigations into school construction.

Police were refusing entry to towns in the quake zone where schools collapsed. About one dozen police and paramilitary troops guarded the gate of Juyuan's destroyed middle school, while a crowd numbering around 50 gathered outside. It wasn't clear whether any of the parents of the 300 children killed in the school collapse were present.

Police last week dragged away more than 100 parents of students killed in Juyuan during a protest. Similar protests have taken place in other parts of the quake zone.

About 7,000 classrooms altogether collapsed in the quake, often in areas where no other buildings were badly affected. Parents and some engineers tasked with surveying the wreckage say the collapses appear to point to poor design, a lack of steel reinforcement bars in the concrete, and the use of other substandard building materials.

Senior military leaders said the threat posed by quake-formed lake has ended.

"As of June 10, Tangjiashan quake lake is no longer considered dangerous," said Senior Col. Wen Zhixiong, deputy director general for the Operations Bureau of the People's Armed Police Force.

Wen said soldiers and police had worked around the clock for nine days to dig a 1,600-foot-long sluice to release the lake's rising water. Some 700 soldiers trekked on foot to deliver three tons of dynamite, diesel and other materials, he said.

Soldiers dug a diversion channel and blasted boulders and large debris with dynamite, bazookas and recoilless guns to speed up the drainage. On Tuesday, churning waters poured through the spillway, engulfing low-lying, empty towns but sparing larger areas downstream.

Maj. Gen. Ma Jian, deputy chief of operations, said the military suffered only five deaths during rescue efforts: the crew aboard a chopper that crashed May 31 as it was ferrying 13 injured from the quake zone.

On Wednesday, a relief helicopter made a forced landing near the quake-hit city of Shifang in Sichuan province after a mechanical breakdown, injuring three people, the official Xinhua news agency reported. The helicopter, carrying 13 relief workers and crew members, landed in an open field, it said.

At the Taohuashan camp overlooking the town of Qinglian, about 3,000 evacuees were still waiting to return home. Authorities had told them they needed to disinfect the area before it would be safe.

Evacuees were suffering from exposure, with 10 people recovering in a clinic from heat stroke and numerous cases of the common cold.

Xu Daijin, a 56-year-old farmer, said he was eager to get back to his crops of beans, gourds, and chili, on which he relied for six months of income totaling about $723.

"I'm relying on the government to help me. I have no choice. I have nothing left," said Xu, who was tending to a pair of pigs he kept in a pen a short distance from the tents.

China has ordered government departments to cut spending to free up reconstruction funds for the estimated 5 million people made homeless, few of whom had insurance.

Citing the China Insurance Regulatory Commission, Xinhua said companies had paid $41 million on 249,000 life and property claims. In contrast, insurance companies have paid more than $40 billion on 1.7 million property loss claims linked to Hurricane Katrina in 2005.

Planning experts have recommended that more than 30 towns in the quake-hit areas, including the local government seat of Beichuan, be rebuilt elsewhere, according to Caijing, a leading Chinese business magazine.

Beichuan may be relocated to the adjacent town of Anxian, and political divisions could be readjusted, Caijing reported.