More than 900 firefighters are battling a blaze that erupted after a powerful explosion ripped through a pesticide plant in eastern China on Thursday, killing at least six people and badly injuring dozens of others, including children. State-run news agency Xinhua reported that the blast occurred at a plant owned by Jiangsu Tianjiayi Chemical at the Chenjiagang Industrial Park in Yancheng, Jiangsu province, just before 3pm. The explosion was so powerful that the China Earthquake Administration reported that it had detected a magnitude 2.2 earthquake believed to be from the blast. “Workers were trapped after buildings were knocked down by the shock wave, which also shattered windows of nearby homes,” Xinhua reported. “Witnesses said many workers were seen running out of the factory covered in blood after the blast.” The Yangtse Evening Post reported that windows of nearby residential buildings and a school were shattered and dozens of cars parked nearby were badly damaged. Many people were injured by the flying debris and residents helped to take the injured to hospital, it said. Shanghai-based news outlet Thepaper.cn reported that 176 fire trucks and 928 firefighters were at the scene and at least 31 seriously injured people had been rescued. A notice posted by the Yangcheng Ecology and Environment Bureau said air quality monitoring teams had been sent to check if there was any water or air contamination near the site. Thepaper.cn also reported that Zhai Qing, vice-minister of ecology and environment, was leading a work team overseeing the monitoring. In addition, Wang Haoshui, chief engineer of the Ministry of Emergency Management, was on the ground helping city authorities respond to the emergency. Beijing Youth Daily reported that the explosion was caused by benzene and occurred in a production area of the pesticide plant. It was not clear if any of the chemical had polluted the area. Benzene is irritating to the eyes and skin, and may cause lung damage if swallowed. Prolonged exposure can also cause cancer. Meanwhile Yancheng’s education bureau said pupils were among those injured in the explosion. Online maps of the area indicate that there are at least 10 schools within a 5km radius of the site. A witness surnamed Xie living about 1.5km from the plant told the South China Morning Post all her windows were shattered by the blast. She said the Chenjiagang hospital was overwhelmed with injured people. Another resident about 40km from the plant said she heard a loud boom and felt the explosion at her home. In 2015, 173 people were killed in two huge explosions at Binhai New Area of the port city of Tianjin in north China. Investigations later showed that a large quantity of explosive materials stored in a warehouse set off the blasts. Jiangsu Tianjiayi Chemical was established in 2007 with registered capital of 90 million yuan (US$13 million). Its business includes the manufacture of chemical products such as hydroxybenzoic acid. In the past, the company has received six administrative punishments for failures regarding solid waste management, environmental impact assessments and air pollution.