At least 65 people have been killed and hundreds of people are missing as of Sunday morning in rainstorm-triggered landslides which hit northwest China's Zhouqu County, Gannan Tibetan Autonomous Prefecture in Gansu Province, said Mao Shengwu, head of the prefecture, Xinhua reported.
"Torrential rains began to fall at around 10:00 p.m. Saturday, then there were landslides and the power of the county was cut," said Diemujiangteng, head of the county.
"The water of the Bailong River then flowed into the county seat and many people were trapped. Now the sludge became the biggest problem to rescue operations. It's too thick to walk or drive through," he said.
Peng Wei, head of the county's fire department said, "the county was in a valley and the river runs in the middle."
"Many toppled houses have formed new barriers to the floods," Pend added.
The water in the barrier lake began to flow to the downstream after an initial explosion, and a total of 19,000 people living in Shawan and Lianghekou townships downstream have been evacuated.
The landslides occurred at around 00:00 a.m. Sunday in Zhouqu County and a barrier lake was formed on the Bailong River which runs through the county at around 1:00 a.m..
At least 50,000 people were believed to be affected as floods had submerged half of the county and many houses were buried by landslides, local authorities said.
Sludge as thick as one meter was formed on some streets of the county.
Two helicopters carrying demolition experts have left for the landslide-hit county at 6:30 a.m. Sunday to explode the barrier lake, according to the provincial flood relief headquarters.
Medical teams and 2,800 troops were also sent to the county by the PLA Lanzhou Military Area Command, according to the headquarters.
Rescuers are searching for the missing people.