An explosion at a fireworks factory in southern China killed 11 workers and injured 17 others, state media and a local official said Saturday, Nov 2, according to the Associated Press.

Most of the victims were female workers who were assembling fuses for firecrackers, the official Xinhua News Agency said. It said the blast took place on Friday and reduced the factory in the city of Cenxi in the Guangxi autonomous region into rubble. It shook nearby buildings and blew out windows.

The cause was not immediately clear.

A man reached at the Guangxi Work Safety Bureau said that two factory executives were detained. He gave no other details.

Cenxi is about 2,000 kilometers (1,200 miles) southwest of Beijing.

Workplace safety is a major problem in China where enforcement of laws is lax with factories themselves usually left to decide whether to follow them.