Heavy rain in China's Sichuan province disrupted efforts to drain lakes that are threatening survivors of the country's deadliest earthquake in 32 years.

The weather is preventing helicopters carrying earthmoving equipment from flying through the mountainous region, where a lake in Tangjiashan is putting 33 townships at risk, state-run Xinhua News Agency reported. The China Meteorological Administration today issued a heavy rain warning for northeast Sichuan, including the disaster zone.

About 160,000 people are being relocated and the government may have to evacuate as many as 1.3 million after landslides caused by the May 12 quake blocked rivers, creating 35 lakes. Some of them are threatening to burst their banks.

The death toll from the quake rose to 68,516 people with 19,350 missing, the State Council Information Office's spokesman, Lu Guangjin, said today. More than 15 million people were displaced in the disaster.

The Finance Ministry allocated a further 1 billion yuan ($144 million) to work on the lakes and reinforcing dams damaged in the quake, it said in a statement. It earlier allocated 400 million yuan for the work.

About 600 military engineers and soldiers, using 29 excavators and bulldozers, were working today through heavy rain to clear debris at the Tangjiashan lake, the biggest formed in Sichuan, and dig a diversion channel, Xinhua said. The area is inaccessible by road and can be reached only on foot or by air.

Mountain Collapsed

The lake contains 130 million cubic meters (34 billion gallons) of water and was created when a part of a mountain collapsed into the Jianhe River.

Forty people close to starvation were rescued from a remote village in the mountains, 16 days after the disaster, the China Metropolitan Daily reported today.

They were stranded by landslides caused by the quake, highlighting the difficulties in accessing the area which sits in the foothills of the Tibetan plateau.

A 5-magnitude quake struck at 12:48 p.m. today, the U.S. Geological Survey said on its Web site, the latest aftershock to hit the area. The aftershocks are disrupting excavation on the lakes and bringing down more rubble from torn mountainsides.

A magnitude 6 quake on May 25 left at least 8 people dead and brought down thousands of buildings already weakened by the main temblor.

Protests Start

Protests have started in some towns near the epicenter with parents surrounding officials and demanding to know why their children died in schools that may have been built below standard, the International Herald Tribune reported today.

An estimated 10,000 children died in the disaster, many in schools that were destroyed while buildings around them were left unscathed, the IHT said. Party officials promised grieving parents the schools would be investigated.

Most people in China are restricted to one child per family to help slow population growth in the world's most populous country. Protests are rare in China.

The government said it will impose harsh penalties on those who withhold or embezzle donations and supplies to the disaster zone, Xinhua reported.

The National Audit Office has received almost 400 reports of misuse or corruption related to relief efforts after announcing a special hotline, according to Zhao Pin in the office's News Department.

China's General Administration of Quality Supervision, Inspection and Quarantine has collected samples of materials such as steel and cement from destroyed schools and has no results so far, the agency's deputy head, Zhi Shuping, said at a news conference in Beijing today.

Collapsing Schools

"Seeing schools collapse and so many students crushed has made everyone very sad, and they naturally think about the issue of the schools' quality,'' Zhi told reporters. "If the damage is really caused by a quality problem, we will take severe measures.''

China has received aid supplies, relief workers and medical staff from more than 40 countries, Zhi Shuping, the deputy director of China's Administration for Quality Supervision, Inspection and Quarantine, said today.

Donations worth 37.3 billion yuan have been received from domestic and overseas sources, State Council spokesman Lu said today. Of that, 10.4 billion yuan has been delivered to Sichuan.

Japan will send three C130 military transport planes to China carrying tents and blankets as early as May 31, the Asahi newspaper reported today.

South Korean President Lee Myung Bak will travel to Sichuan tomorrow to see the disaster zone, the first overseas head of state to visit the area, according to a statement on the presidential office's Web site.

The earthquake was the most powerful to hit China since a magnitude 8.6 quake struck Tibet in 1950, killing 1,526 people.

A 7.5 magnitude temblor in Tangshan in the northeast killed 250,000 in 1976, according to the U.S. Geological Survey. China's seismology department said the Sichuan quake had a magnitude of 8.