Battle against time to drain quake lake

MIANYANG, China (Reuters) - Chinese troops racing to draina swelling "earthquake lake" made progress digging a diversionchannel and officials sought to assure residents that no massevacuation of a nearby city was planned.

The landslide-blocked river at Tangjiashan in southwestChina's Sichuan province is now the most pressing danger afteran earthquake devastated the region on May 12.

The official death toll from the quake is 68,858 and issure to rise with 18,618 missing. Aftershocks have toppled420,000 houses, most already uninhabitable, and there is worrythat landslide-blocked rivers could bring more havoc.

The official Xinhua news agency said Tan Li, CommunistParty Secretary of Mianyang city in the quake zone, issued anorder that 1.3 million people living downstream fromTangjiashan, a swollen quake lake, must "evacuate to higherground".

But Zhou Hua, a Mianyang city official who is spokesman forthe lake relief effort, told Reuters the report was inaccurate.

"There is a virtual training exercise scheduled fortomorrow to test our contingency plan to move that manypeople," he said. "But there is no public participation, and wesee no reason at all to actually implement the plan at thisstage."

Mianyang, a city of 5.3 million people including many inrural areas, has a concentration of high-tech businesses.

At the unstable Tangjiashan lake, hundreds of troops haveremoved more than a third of the earth for a channel intendedto ease pressure from the rising waters in the mountainousprovince of Sichuan, an official spokesman said on Friday.

Up to 190,000 residents downstream had moved to higherground -- usually hillsides close to where they were livingbefore -- to avoid a surge of water if the blockage suddenlygave way, Zhou said.

Xinhua news agency said the water level was nearly 23metres (75 feet) below the lowest point of the barrier, whichexperts have said could give way quickly once breached. Troopshave also built escape paths in the event that happens, Xinhuasaid.

A Chinese meteorological authority official, Zhai Panmao,said the authority did not expect unusually heavy rain in thearea in the next 10 days.

"We've adopted extremely important measures and are openingup a breach and so on," he said. "We have full confidence insolving this problem."

Post-quake reconstruction work has only just begun, andtens of thousands of survivors are now threatened by more than30 quake lakes, formed by landslides, that could break throughthe natural dams, flooding downstream towns and reservoirs.

Japan had shelved plans for its military to fly tents andblankets to China, a Japanese government official said onFriday, after messages on Chinese Internet sites recalled wartime atrocities by Japanese troops.

CHILDREN

Meanwhile, an official investigator pinpointed the poordesign and construction of at least one of the many schoolsthat collapsed during the quake, killing thousands of children.

Domestic media reports compiled by Reuters put the combinedtoll from deaths of children and teachers in the rubble ofschools at more than 9,000. The Chinese public has beenoutraged by the disproportionate number.

An official investigator said one the schools thatcrumpled, the Juyuan Middle School, where hundreds of childrendied, was fatally weakened by poor design and materials.

"There were certainly problems with site selection, thebuilding's structure and structural features, the constructionand materials," Chen Baosheng, an expert from Tongji Universityin Shanghai, told the Southern Weekend.

The number of prospective orphans in the quake area hasdropped dramatically as more children were reunited with theirparents, Xinhua quoted local officials as saying.

There were about 1,000 "unclaimed children" in Sichuan asof Wednesday, down from more than 8,000 immediately after theearthquake, Xinhua said, adding civil affairs authorities hadbeen overwhelmed by calls seeking to adopt those quake orphans.

(Additional reporting by Chisa Fujioka in Tokyo, ChrisBuckley, Guo Shipeng and Beijing newsroom; Writing by NickMacfie; Editing by Sanjeev Miglani)