China has launched a campaign to clean up its internet, state media said on Wednesday, amid a fresh wave of apparent censorship by authorities that has blocked more foreign media websites and shut down domestic accounts on social media.

The “amendment” exertion was launched in May by the internet administration, the data innovation ministry, the open security department and the business sectors controller and will keep running until the year’s end, the official Xinhua news office said.

The campaign will rebuff and uncover sites for “illegal and criminal actions”, failing to “fulfill their obligation” to take safety measures or the theft of personal information, it added.

The campaign pursues a series of shutdowns and blockages of specific websites and social media accounts.

A few outside media outside Beijing’s ability to control, such as the Washington Post and The Guardian, have not been open online since a weekend ago, adding to a rundown of blocked destinations that incorporates Reuters.

Online Chinese financial news publication Wallstreetcn.com said on Monday it took its website and mobile app offline at the authorities’ request, but gave no details of the rules it may have broken.

Social media accounts going from those publishing politically delicate material to financial news have also been shut.

Authorities said in November they shut 9,800 accounts of news providers deemed to be posting sensational, vulgar or politically harmful content.

The Chinese internet regulator’s Shanghai office said in a statement on Wednesday that it and the markets regulator’s Shanghai office summoned representatives from Baidu Inc and criticized the firm for unethical advertising using vulgar content or overly sensational titles.

The authorities requested the search engine operator to amend its publicizing business to take out such works on, as per the announcement, which cited a Baidu agent as saying the firm would roll out important improvements.

As of late, China has routinely battled to police its internet, closing down websites, social media accounts and mobile apps.

“The cleaning drives are not purely political. Many, possibly even most, of those accounts were probably spam, porn or other types of content that the platforms have made clear are undesirable and unwelcome,” said Fergus Ryan, an analyst with the Australian Strategic Policy Institute.

“The problem is that in among those legitimate removals are accounts that are removed for political reasons.”

Shimin Fang, a popular science writer who drew public scrutiny in China for critical comments about telecommunications giant Huawei Technologies Co, said he found out on Tuesday all of his Chinese social media accounts had been taken down.

Fang, who lives in the United States, said he did not know what had happened until some readers told him they could no longer find his postings and that the platform operators would not tell him why his accounts were shut down.

“My guess is that from now on any influential self-media accounts will not be allowed to exist, no matter (if) they are political or not,” Fang told Reuters in an email.

The term “self-media” is mostly used on Chinese social media to describe independent news accounts that produce original content but are not officially registered with the authorities.

“The Chinese internet winter is coming,” Fang said.