At least sixteen people died because of excessively high levels of carbon monoxide after being trapped inside a coal mine in southwest China, Reuters reported, citing Xinhua news agency.

Seventeen miners got trapped in a coal mine in the city of Chongqing, local authorities said. A survivor was taken to a hospital and his condition is critical, according to AFP.

The carbon monoxide was produced after a conveyor belt caught fire early on Sunday morning, the news agency said. The burning of belts in the mine reportedly caused carbon monoxide to exceed safety limits. However, Qijiang district government officials said an investigation was underway to ascertain the cause of the accident.

The Songzao Coal Mine, the facility where the incident occurred, is owned by state energy firm Chongqing Energy and is situated just outside the city of Chongqing.

A rescue team of 75 personnel has entered the mine and 30 medical workers are present at the site.

China has a poor history of industrial safety and has the deadliest mines in the world.

In December 2019, at least 14 miners were killed in a coal and gas blast in a mine in southwestern Guizhou province. Seven miners died in December 2018 in Chongqing after a connecting wire of a skip, a car used to haul ore or country rock, broke and fell down a shaft.

Twenty-one miners were killed in October 2018 in Shandong province after rocks inside a mine fractured due to pressure. The rocks blocked the tunnel and trapped the workers. Only one miner could be rescued alive.