Dozens of people were trapped Wednesday after a two-story building collapsed in southwest China, state media reported.

At least 100 people, mostly retirees, were inside the former agriculture exhibition center in Leshan city, Sichuan province, when it collapsed. More than 30 survivors have been pulled from the rubble and sent to a hospital, Xinhua News Agency said.

No deaths were immediately reported, Xinhua said, citing a spokesman for the city's public security bureau.

The number of casualties was not known, city official Xu Tianyi was quoted as saying.

The two-story exhibition center was built in 1959. It is largely unused except for dances for senior citizens.