Beijing ? A blast ripped through a fireworks factory in northern China, killing 29 people and injuring at least 141, state media said early today.

The explosion took place Monday at the Guoxi fireworks factory in the town of Wangkou in Hebei province, China Central Television said in its noon newscast.

It wasn’t immediately clear how many workers were in the factory at the time.

“I thought it was an earthquake. I was really scared. My sister and I just ran out of the house,” Qian Yun, a 19-year-old living about three miles away from the factory, said by telephone.

Another villager, Zhang Fangjie, was working on his farm at the time.

“I heard three or four explosions in a row and saw black smoke rising in the distance,” the 40-year-old Zhang said.

The injured were hospitalized and 50 people with minor injuries were released, CCTV said.

The blast completely destroyed the main workroom at the factory and buildings up to 300 feet away were damaged, the official Xinhua News Agency said.

The cause of the explosion was under investigation, Xinhua said.

Fatal explosions are frequent in China’s fireworks factories despite a safety crackdown launched in early 2002 following a series of high-profile accidents.

The industry employs hundreds of thousands of people, many working at home or in small factories where most manufacturing is done by hand.