A powerful explosion ripped through an industrial park in eastern China on Thursday, killing at least six people and injuring over 30 others as it knocked down factory buildings, local officials said.

The explosion occurred at about 2:48 pm following a fire in a fertilizer factory in a chemical industrial park in Yancheng, Jiangsu province, according to the government of Xiangshui county.

Eye-witnesses said several workers were trapped after buildings were knocked down by the shockwave stated to be a mild tremor caused by the blast which took place in a pesticide plant. The blast also shattered windows of nearby residential houses.

They said many workers were seen running out of the factory covered in blood after the blast, which also shattered windows of many nearby residential houses and damaged cars in the vicinity.

State-run Xinhua news agency reported that 12 people have been rescued after the explosion.The firefighter brigade of Jiangsu said they had mobilized 86 fire trucks to join the rescue mission.

Yancheng’s education department said school students were among those injured in the explosion. Online maps of the area indicate that there are at least 10 schools close to the site.Beijing Youth Daily reported that the explosion was caused by benzene and occurred in a production area of the plant.