Demonstrators call for press freedom in support of journalists from the Southern Weekly outside the newspaper’s offices in Guangzhou, in China’s southern Guangdong province, on Tuesday. (AFP/AFP/GETTY IMAGES)

The Chinese government’s main propaganda organ took a hard line Tuesday against anti-censorship protesters at the offices of the Guangdong newspaper Southern Weekly, declaring that Communist Party control over Chinese media is “unshakable” and accusing “external” agitators of fomenting the unrest.

The “urgent memo” from the ruling party’s Central Propaganda Department was sent to media heads and local party chiefs. It was obtained and translated into English by the Hong Kong newspaper South China Morning Post and the Web site China Digital Times, which regularly publishes edicts from China’s censorship authorities, derisively known as the Ministry of Truth.

“The party has absolute control over the media, and this principle is unshakable,” the memo said. “External hostile forces are involved in the development of the situation” at Southern Weekly.

The memo added that every “work unit” must immediately “demand that its department’s editors, reporters and staff discontinue voicing support for Southern Weekly online.”

The protests began last week when the reform-minded paper’s editors and reporters complained that a front-page New Year’s Day message to readers — voicing the “dream” that China would soon have constitutional rule — was substantially rewritten and watered down into an obsequious tribute to the Communist Party. The editors said the text was rewritten without their knowledge by the party’s Guangdong propaganda chief, Tuo Zhen, who has become the principal target of the demonstrators’ ire.

What began as a largely online protest by Southern Weekly journalists quickly gathered steam around the country, drawing support from noted actors, writers, business leaders and others who have used their weibo accounts — the Chinese version of Twitter — to decry heavy-handed government censorship of Chinese media and demand more freedom of expression. The rare show of discontent has posed a crucial test for China’s new leadership team, led by party Secretary General Xi Jinping.

Hundreds of anti-censorship protesters donned masks, chanted slogans and left flowers at the newspaper’s headquarters in Guangzhou, the capital of Guangdong province, on Monday, and smaller crowds continued the protest Tuesday. But this time they were met by “new leftists,” who carried pictures of the late party leader Mao Zedong and voiced support for government control. The groups clashed verbally during the demonstration.

Police have largely stayed on the sidelines and let the protests continue — a rarity in China, where public demonstrations are normally not allowed. But Tuesday, police officers were photographed installing security cameras around the paper’s headquarters, presumably to film the protesters.

The memo from the Central Propaganda Department also ordered all media and Web sites in China to “prominently republish” a hard-line editorial that appeared Tuesday in the Global Times, a nationalist tabloid owned by the party’s main mouthpiece, the People’s Daily.

The editorial blamed “activists,” including blind, self-taught lawyer Chen Guangcheng, who is in the United States, for stirring up the censorship issue. “Some activists outside the media industry in China have been inciting some media to engage in confrontation,” it said. “Those external activists are expecting direct confrontation between Chinese media and the current system.”

The editorial also asserted that “under the reality of China’s current state of affairs, the country is unlikely to have the ‘absolutely free media’ that is dreamed of by those activists.”

Newspapers dutifully began reprinting the editorial Tuesday, as ordered, but in an unusual act of defiance, many editors added a note saying the editorial did not represent their paper’s viewpoint.

The censorship battle took a new turn Wednesday when it was reported that Dai Zigeng, a Communist Party official who is publisher of the Beijing News, resigned overnight in protest after being forced to print an editorial from the Global Times blaming foreign activists for the current unrest. The resignation was reported by Beijing News journalists on social media sites and by the South China Morning Post. In China, Dai’s name and the name “Beijing News” were blocked from social media search engines.

Sources familiar with the Beijing News case said Dai’s dramatic resignation came after a tense late-night standoff that lasted several hours, between a government propaganda official, who ordered the paper to run the Global Editorial or see the entire newspaper shut down, and the staff members who stood in protest.  The paper finally ran the editorial, but in the news pages as a news story, not on the normal editorial page, and sources said some staffers were in tears.

Details of the resignation could not be independently confirmed.  A spokesman at the Beijing government propaganda office said everything was “normal” at the newspaper.

Meanwhile, reports from Guangzhou said Southern Weekly journalists had reached an agreement with local authorities that would allow the next issue of the newspaper to come out as planned on Thursday. Some reporters and editors had said they intended to strike over the censorship issue.

In an editorial on Friday, the Global Times suggested that the kind of intrusive censorship that allegedly occurred at the Southern Weekly is routine in China. “Realistically speaking,” it said, “many Chinese media outlets have experiences of major reports being altered by officials.”

Hu Jia, an activist and friend of Chen’s in China, said that Chen, who is studying in New York, had been asked by foreign media to comment on the Southern Weekly situation but had no direct involvement in any protest. Hu said the communist authorities here have routinely tried to blame internal problems on activists overseas to divert attention from their own inability to maintain strict control.

Liu Liu contributed to this report.