Beijing's first air class-action lawsuit related to pollution began an open hearing session at the city's No 4 People's Court on May 8.

The defendant in the case is Duocai Lianyi Co, a steel and paint operation in Daxing district. Prosecutors say Duocai has been polluting the air and has failed to install devices to reduce emissions in accordance with regulations.

"The company has harmed the surrounding environment," prosecutors said during the trial. "We filed the lawsuit to seek a court order for it to halt emissions, and we are seeking compensation for the pollution it has caused as well as a public apology."

Lawyers for Duocai said the company had already halted emissions after receiving an order to do so from the district environmental authority as well as paid 200,000 yuan ($31,435) in fines.

They added that the company would enhance pollution controls further if a new environmental evaluation leads to such a recommendation.

The verdict will be announced at a later date, the court said, without providing a more specific time frame.

Under the Civil Procedure Law revised last year, prosecutors have the power to initiate class-action lawsuits against enterprises that damage the public interest, such as those polluting the environment or compromising food safety.