NANCHANG -- Five people have been confirmed dead in a residential building collapse in East China's Jiangxi Province, after rescuers retrieved four more bodies Saturday.

One person remains missing as of 10 p.m. Saturday, according to officials with the emergency rescue headquarters in Pingxiang City.

Rescuers managed to pull nine people from the debris on Friday, with one dead and one injured, both of whom were construction workers. The other seven residents are in stable condition, rescuers said.

The upper levels of a six-story building crumbled in Xinxueqian Alley in Anyuan District at around 2:18 p.m. Friday. Six families lived on the fourth, fifth and sixth floors.

"I thought it was an earthquake. I heard a loud bang and felt vibrations," said Zhong Zhiyong, who was home with his three-year-old grandson in their sixth-floor apartment when the accident happened. "When I opened the door I saw the stairs had disappeared."

Firemen used a scaling ladder to rescue Zhong and the child.

The building, which was home to about 30 households, was constructed in 1983. Huang Yongqing, who owns one of the ground floor shops, said renovation was underway on the fourth floor. "An old building like this cannot withstand such activity," he said.

Investigators are yet to announce the cause of the accident.

"The renovation work could be one of the reasons, but we still need further analysis," said an official with the provincial housing and urban-rural development department.

He said the upper three floors of the building were made from brick and concrete, adding that there were signs of unauthorized structures on the roof.

Two cranes were cleaning the debris Saturday. "At least 100 tonnes of debris needs to be cleared, but we have to work slowly and carefully as more people may still be buried," said Zeng Xianglin, a rescuer.

He said the cleaning would take more than 30 hours.

The provincial government issued a circular Saturday demanding building safety in old residential communities.