SHIJIAZHUANG, May 9 (Xinhua) -- Four people have been killed and 11 injured in an explosion in north China's Hebei Province, the local government said on Wednesday.

The explosion occurred at 9:35 a.m. Wednesday between two houses in Xiakou Village, Pingshan County, a spokesman of the Pingshan county government said.

The two houses, belonging to Peng Xianhai and Peng Huangxiao, were completely devastated. Four elderly family members of the two house owners were killed but no further details were provided by officials.

The blast also destroyed a few buildings in a nearby secondary school where some students were injured by flying glass.

The cause of the blast has not been revealed but local residents believe explosives used for mining could have been detonated.

The injured have been taken to a local hospital.