Police in northern China's Hebei Province have arrested nine suspects for a fatal discharge of industrial waste.
The illegal dumping of waste hydrochloric acid killed five people and injured two others in mid-June in Wuji county, Shijiazhuang city.
Toxic gas produced during the dumping process poisoned the people who were paid to do the job.
The suspects include the representatives of three local chemical companies.
The local government launched a crackdown on illegal waste dumping on June 17, seizing 83 suspects and busting eight criminal gangs.