Beijing authorities have shut down several edgy news programs run by major web portals in the latest round of efforts to restrict reporting of political and social news.

Citing violation of rules, the municipal office in charge of cyberspace regulations have ordered news portals of Sina, Sohu, Netease and iFeng to end their news programs known for more freewheeling coverage of political and social news, the state-run Beijing News reported Sunday.

The government office did not immediately respond to requests for comment from The Associated Press.

By law, Chinese news sites are allowed to carry only political news reports from state media controlled by party committees and governments. Despite the clear rules against news sites having their own news gathering teams, major news sites — driven partly by commercial interests and partly by their journalistic pursuits — have formed their own editorial staffs to chase hot social issues and conduct in-depth investigations.

In the past few years, in envelope-pushing moves, the news sites have hired many veteran investigative journalists displaced from traditional media that have come under tighter controls, and those journalists — despite working without accreditation — have produced long, edgy pieces on social issues, such as environmental protests over trash incinerators and the touchy topic of education inequity. Those programs have over time become popular among readers.

Authorities have long turned a blind eye to news sites hiring their own staffs to report on non-sensitive news, such as entertainment and sports, but are always wary of any editorial efforts on sensitive topics outside direct government control.

The closure of the news programs run by the websites further restricts China's investigative news reporting, said a Beijing-based journalism professor, who requested anonymity because of the sensitivity of the topic.

"It's becoming more difficult," the professor said Monday. "There's very little room left now for in-depth reporting."