Firefighters check the sewage system.
Firefighters spray water into the air in the area affected by the toxic gas.
The police and fire department in Dongguan, Guangdong Province have launched an investigation after toxic chlorine gas was allegedly illegally disposed of in the sewage system.
Chlorine is a toxic gas that irritates the respiratory system and it may react with flammable materials, but there have not been any confirmed reports of poisoning relating to this case.
The odor polluted the air in Changtai Road and Dongjun Road, bringing traffic to a halt for nearly three hours.
Firefighters sprayed water into the air in order to dilute the odor.
One local resident named Chen Jing said that he saw a truck in the area that diffused the strong smell of chlorine, and two people had collapsed as they walked by the vehicle.
The Environment Protection Agency said it thinks this is a case of illegal disposal of toxic gas.
