An explosion killed seven and injured 13 Wednesday morning at a workshop of a fireworks factory in central China's Hunan Province, according to local publicity department.

The blast occurred at around 7:50 a.m. in a fireworks factory in Chengtanjiang Town, in the city of Liuyang due to illegal production.

The injured have been sent to the hospital. 

The site of the accident has been closed and those in charge of the fireworks company were taken into police custody.

A team was formed to investigate the accident.

(With input from Xinhua)