CHANGSHA, Nov. 23 -- A cesspool filled with excrement exploded in a central Chinese city, injuring 15 residents and toppling a building on Saturday, police said.

Police in Zhangjiajie city, Hunan Province, believed it was an accident when a man surnamed Ding was burning waste outside his derelict house and near the cesspool at about 5 p.m..

Police said the fire ignited the methane emanated from the pit and caused the blast. The house has been abandoned since 2006.

The blast occurred at Dayongqiao community of Yongding District. One residential building collapsed, and four others were damaged.

The injured people have been hospitalized. Local residents have been settled properly.