The fight to drain a dangerous debris-formed lake gained new urgency Wednesday amid fears that a breach could bring further devastation to a northwest China county that was leveled by the country's deadliest mudslide in decades on Sunday. The weather bureau warned Wednesday of heavy rains and more potential geological disasters in the next five days on the upper reaches of the Bailong River, above Zhouqu County, in Gannan Tibetan Autonomous Prefecture of Gansu Province.

China's Ministry of Health has sent six top-level specialists on epidemic prevention to mudslide-hit county of Zhouqu as a part of the latest efforts to prevent the outbreak of a medical epidemic. 

Latest development:

A 50-year-old man was freed Wednesday after more than three days trapped in knee-deep sludge from deadly mudslides that ravaged Zhouqu County in northwest China's Guansu Province.

UN Secretary General Ban Ki-moon on Tuesday extended his deepest sympathy and condolences to the government and people of China over the loss of life and devastation caused by the severe mudslide in northwestern China.

Rescuers prepare to disinfect a landslide-hit street in Zhouqu County of Gannan Tibetan Autonomous Prefecture, Gansu Province August 11, 2010. The death toll has risen to 702, with 1,042 others still missing by Tuesday afternoon.

Rescuers use boats to bring locals to a safer area on a flooded street in landslide-hit Zhouqu County of Gannan Tibetan Autonomous Prefecture, Gansu Province August 10, 2010. 

A view shows the landslide-hit Zhouqu County of Gannan Tibetan Autonomous Prefecture, Gansu Province, Gansu Province August 10, 2010. 

The hunt for survivors entered its fourth day Wednesday, with troops still searching the ruins with life detectors and sniffer dogs. Volunteers help rescuers in Zhouqu（L）,Residents of Zhouqu county receive pancake.(R)

Women mourn their missing relatives in the landslide-hit Zhouqu County of Gannan Tibetan Autonomous Prefecture, Gansu Province , Gansu Province August 10, 2010.

A man mourns his missing relatives in the landslide-hit Zhouqu County of Gannan Tibetan Autonomous Prefecture, Gansu Province August 10, 2010.