Chinese police arrested a building owner and eight other people Sunday, two days after the structure collapsed, leaving dozens trapped or missing, police and state media said.

The official Xinhua News Agency said the building owner was among the arrested. Police in the city of Changsha said they had also arrested three people in charge of design and construction and five others for what they said was a false safety assessment for a guest house on the fourth to sixth floors.

Five people had been rescued as of late Saturday, more than 24 hours after the collapse. About 20 remained trapped, and another 39 had not been accounted for.

In photos the building appeared to have pancaked down to about the second floor, leaving rubble strewn on the sidewalk. It had stood in a row of buildings about six stories tall in Changsha, the capital of Hunan province.

Xinhua said the building had eight floors, including a restaurant on the second floor, a cafe on the third floor and residences on the top two floors. Other media reports said it was a six-story building. Tenants had made structural modifications to the building, but the cause of the collapse remained under investigation, Xinhua said.

Police said the Hunan Xiangda Engineering Testing Co. issued the false safety report on April 13. The arrested included the legal representative of the company and four technicians suspected of providing the assessment.

Following an increase in the number of collapses of self-built buildings in recent years, Chinese President Xi Jinping said Saturday that it was necessary to check such structures for any hidden dangers and fix them to prevent major accidents, Xinhua said.

Poor adherence to safety standards, including the illegal addition of extra floors and failure to use reinforcing iron bars, is often blamed for such disasters.