Over 10,000 people have been evacuated from a suburb of the southwestern Chinese city of Nanchong over a reported ammonia leak from a fertilizer plant.

Residents of the Dingshui district in Nanchong were forced to flee the area on Monday night after the toxic gas leaked from a pipeline operated by the Chuanlong Chemical Company, the West China City Daily reported the next day.

Many of the residents escaped from the district in cars, on motorcycles, by bicycles or even on foot, resulting in heavy traffic jams on nearby roads.

News reports said Tuesday that police and firefighters managed to contain the leak, and a number of residents had returned home.

Launching an investigation into the incident, local officials said they had informed residents to leave the area immediately after the leak was detected.

Exposure to high levels of ammonia, a toxic gas with a pungent smell, can result in death due to swelling in the throat or chemical burns to lungs.