The announcement came within weeks of the surprise departure of the Cyberspace Administration’s director, Lu Wei, and his replacement by an official who had served under President Xi Jinping in a previous position. Under Mr. Xi, media controls have tightened as the Communist Party has tried to squelch news that might put its governance in an unfavorable light.

Image China’s order to several popular internet portals that they halt much of their original news reporting came within weeks of the surprise departure of the Cyberspace Administration’s director, Lu Wei. Credit... Reuters

In February, Mr. Xi visited three of the top state-run news organizations, telling their staffs in a highly choreographed tour that they existed to serve as propaganda messengers for the party. This month, a respected scholarly journal run by retired Communist Party cadres shut down after a quarter-century following the dismissal of its founding publisher.

The edict made public on Monday, which said the web portals were in “serious violation” of a 2005 internet regulation, came before a meeting next year of the Communist Party Congress. The party often puts in place controls on news before important events, such as the party conclave, held once every five years, which will pick a new group of senior leaders.

The news sites are run by China’s biggest internet companies, which also operate social media platforms and produce some of the country’s most popular online games. Sina, which runs a news aggregation service and publishes original reporting, also created Weibo, China’s popular Twitter-like social media site. The companies are roughly the equivalent of the United States’ largest internet companies, like Facebook, Twitter and Google, and their news sites combine articles from other outlets with original reporting and investigative journalism.

It is unclear whether the regulation will end all original reporting at the websites, where hundreds of millions of Chinese turn for their news. Monday’s announcement mentioned specific features at four internet sites, which in recent years have attracted investigative reporters from newspapers such as Southern Weekend. It was among the first news organizations to face restrictions after Mr. Xi became head of the Communist Party in November 2012.