South Africa’s environment minister and the national air quality officer have been sued by environmental activists for allegedly not acting against ArcelorMittal South Africa Ltd. over its air pollution.

The case was filed by the Vaal Environmental Justice Alliance and groundWork, they said in an emailed statement on Tuesday. The suit mirrors an earlier case, won by activists, against the government over air pollution from plants operated by Eskom Holdings SOC Ltd. and Sasol Ltd.

ArcelorMittal South Africa and the environment department didn’t respond to a request for comment.