Photo: CCTV

SHIJIAZHUANG, Nov. 13 (Xinhua) -- Seven people were killed and another injured in an explosion at an expanded polyethylene factory in north China's Hebei Province, the local government said Friday.

The blast occurred at around 6 p.m. Thursday in the province's Wuji County, according to the county government.

Rescue forces immediately rushed to the scene. Search and rescue work is generally completed.

An investigation into the cause of the blast is underway.