Heavy smoke is seen at the accident site after a blast ripped through a factory workshop and triggered a fire in the Xiannu Township of Zhijiang City, central China's Hubei Province, May 23, 2012. The casualties are not immediately known in the accident, which took place at about 10 a.m. on Wednesday. Firemen are struggling to put out the fire, a municipal government spokesman said. (Xinhua/Zhao Zhonghua)

An explosion ripped through a factory in central China's Hubei province Wednesday, injuring at least five people, local authorities said.

The accident took place at 10 a.m. at a plastics factory in Xiannu township in the city of Zhijiang, a municipal government spokesman said.

Firefighters are struggling to put out a fire ignited by the blast, the spokesman said.