BERLIN — A prominent German environmental group said Wednesday that it’s suing Facebook’s parent company Meta over persistent death threats posted on the social network against its staff.

Environmental Action Germany, known by its German acronym DUH, says Meta has failed to take steps to stop the threats of violence regularly directed at DUH director Juergen Resch and others in a Facebook group with more than 50,000 members.

DUH has conducted high-profile campaigns demanding that German cities enforce air quality rules by banning certain heavily polluting vehicles. This has drawn ire from car enthusiasts.

Meta said in a statement that it actively works to stop hate speech on its platforms.

“We are constantly investing in technology and reporting tools so that hate speech can be identified and removed even faster,” the company said. “In this case, we have removed the content that was reported to us.”

German lawmaker Renate Kuenast won a case against Facebook last year forcing the company to remove fake quotes attributed to her from its site and pay damages. Facebook is appealing the ruling.