GUIYANG, May 20  -- Twenty-one residents of a nine-story building that collapsed in Guiyang, capital of southwest China's Guizhou Province on Wednesday, are unaccounted for as rescuers comb the rubble for survivors or bodies.

Authorities said 114 residents live in the 35-household apartment building, which collapsed at 11:30 a.m. in Yunyan District. Ninety-three of the residents have been confirmed safe.

A man surnamed Zhang who lived on the ground floor was pulled out by rescuers. He told Xinhua that he was awakened by loud noises. He was about to run from the building when he was buried by falling debris.

Another resident who declined to give her name was worried about her daughter-in-law. "She lived on the ninth floor," she said. "I called, but couldn't reach her."

Residents of nearby buildings were evacuated after the accident.

The cause of the accident is being investigated.