Protesters rallied Tuesday for a second day to call for press freedom in China, as social media users and celebrities backed a campaign which poses a test for the nation's new leaders.

Scores of people, some carrying mourning flowers, gathered outside the Guangzhou offices of the Southern Weekly, a popular liberal paper which had an article urging greater protection of rights censored.

"The government is using the media for their purposes," said a 24-year-old man surnamed Leung. "If we don't step out now to support this newspaper and call for greater freedom, our society will have less and less space for freedom."

Some demonstrators wore masks depicting British revolutionary figure Guy Fawkes, adopted as an anarchist symbol internationally after being popularised in the film "V for Vendetta" -- which was recently broadcast on state television.

Police stood by, allowing the rally to proceed. As it dispersed for the day a lone woman demonstrator stood outside the building, holding a white rose and raising one hand, making a victory sign with her fingers.

Some protesters traded insults with around a dozen rivals who showed support for the authorities. A few held up portraits of Mao Zedong, the founding father of communist China.

Protests about explicitly political issues such as rights are very rare in China. The dispute comes after the ruling party's new leadership headed by Xi Jinping took over in November, raising expectations of a more open style of governance.

The second day of demonstrations came after bloggers and celebrities -- some with millions of followers -- voiced support online for freedom of the press.

Yao Chen, an actress who has 32 million followers, posted the paper's logo on China's Twitter-like Weibo service and quoted Russian dissident Alexandr Solzhenitsyn: "One word of truth shall outweigh the whole world".

Fellow actor Chen Kun, who has 27 million followers, replied: "I am not that deep, and don't play with words, I support the friends at Southern Weekly".

Media outlets are subject to directives from official propaganda departments, which often suppress news seen as negative by the communist authorities.

The row erupted after censors blocked Southern Weekly's New Year message calling for the realisation of a "dream of constitutionalism in China". They replaced it with an article in praise of the Communist Party, according to journalists.

In an open letter journalists blamed provincial propaganda official Tuo Zhen and called for his resignation.

Journalists on the paper said on condition of anonymity that staff and "relevant government departments" were negotiating to end the dispute. They declined to go into details because of the sensitivity of the talks.

"I can't be sure if the newspaper will be published on Thursday or not," said one, but added the reporters were not on strike.

The authorities seemed to be approaching the row cautiously to avoid a backlash that might trigger more protests, said Doug Young, a journalism professor at Fudan University in Shanghai.

"The government is treading really, really carefully in this incident because they have to make sure that it doesn't get out of control, say if they come across as acting too heavy-handed and start arresting people or trying to fire people," he said.

A commentary in the People's Daily, the party's mouthpiece, said propaganda chiefs should adapt to the "rhythm of the era" to ensure their effectiveness, and abandon "stiff preaching that is unchanging and patronising".

But the English-language Global Times, which is also close to the ruling party, said there would be no radical changes in media policy.

"The country is unlikely to have the 'absolutely free media' that is dreamed of by those activists," it said. "Media reform should be in line with China's politics."

The US-based China Digital Times website posted what it called a message from propaganda authorities, telling media that party control was "an unwavering basic principle" and they should "prominently republish" the Global Times article.

But in an unusual move, major web major portals carrying it in Chinese -- Sina, Sohu, Tencent and Netease -- posted disclaimers. The message on Sina said its republication "does not mean that our website agrees with its opinion or verifies what it describes".

Analysts said the dispute was the latest instance of years of mounting tension between a heavily controlling government and a public increasingly assertive of its rights.

"It's part of the intensifying battle in the last decade," said Kerry Brown, director of the China Studies Centre at the University of Sydney. "You cannot just shut them up. This is not going to go away."