BEIJING (AFP) - Protestors gathered on Monday at the offices of a Chinese newspaper at the centre of a censorship row to call for media freedom, in a rare demonstration on the subject in the country.

Hundreds of people were protesting outside the Southern Weekly's office in Guangzhou, according to online reports, with one banner reading: "We want press freedom, constitutionalism and democracy."

The demonstration in the southern city came after censors blocked a New Year article in the popular liberal newspaper calling for the realisation of a "dream of constitutionalism in China" to protect citizens' rights.

All Chinese media organisations are subject to instructions from government propaganda departments, which often suppress news seen as "negative" by the ruling Communist Party, although some publications take a more critical stance.

The censorship at the Southern Weekly sparked online uproar from netizens, including the newspaper's staff.

Some Internet reports said the staff launched a strike on Sunday after senior editors took control of the newspaper's microblog posts from day-to-day journalists.

An open letter from staff at the newspaper called for the resignation of provincial propaganda official Tuo Zhen, who was said to have removed the New Year message and replaced it with a weaker article.

It was an unusually vocal and public response to the authorities' moves, and the demand was echoed by another open letter from dozens of interns at the newspaper.

A third letter, signed by scores of prominent academics from across China, emerged over the weekend, also calling for the immediate removal of Mr Tuo and for more press freedoms.

Asked about the Southern Weekly article at a regular press briefing last week, a foreign ministry spokesman in Beijing said: "There is no so-called news censorship in China."