Seventeen people were found dead and 17 others remained missing after sudden mud-rock flows triggered by torrential rain hit villages in northwest China's Qinghai Province early Thursday, Xinhua news agency quoted local authorities as saying at a press conference.

Twenty people who were previously reported as missing have been rescued. Some 4,500 firefighters, policemen, servicemen, emergency response personnel and local residents are still looking for the missing people, Han Xianghui, vice head of the provincial emergency management department, told the press conference.

The heavy rainfall, starting at 10:25 pm Wednesday, lashed Datong Hui and Tu Autonomous County in the provincial capital Xining. By midnight Thursday, the downpours triggered flash floods and mudslides and caused rivers to change courses.

A total of 6,245 residents in six villages have been affected, as at least two buildings were washed away and 14 buildings were seriously damaged.