BEIJING (AFP) - A liberal Chinese journal had its website shut down on Friday, it said, after it urged the country's Communist leaders - who regularly promise reform - to follow the constitution.

The website of Annals of the Yellow Emperor, a prominent Beijing-based publication, was closed days after it published an article arguing that China's constitution lays out a roadmap for political change.

Attempts to access the website on Friday led to a page with a cartoon policeman holding up a badge and the message: "The website you are visiting has been closed because it has not been filed on record."

The move follows a similar call in a key liberal newspaper being censored by the authorities.

Chinese liberals argue that rights enshrined in the constitution, including freedom of speech, press and assembly, are not respected by the ruling Communist party.

"At around 9am today, the website was closed," said a post on the Annals of the Yellow Emperor's official web page on Sina Weibo, a website similar to Twitter.

The journal's editors received a message from Internet regulator, the Ministry of Industry and Information Technology, last month stating that the website had been "cancelled", the post said.

The website closure came a day after censors blocked an article from popular liberal newspaper Southern Weekly which called for the realisation of a "dream of constitutionalism in China" so that citizens' rights could be protected.

A propaganda official in Guangdong province, where the newspaper is based, removed the article and replaced it with a weaker message, said several current and former journalists at the newspaper.

The official Tuo Zhen "directed that many alterations and replacements be made to the New Year's special edition. This resulted in numerous errors and accidents", former Southern Weekly journalists said in an open letter posted online.

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

China was the 174 lowest of 179 countries ranked for press freedom in 2011-12 by the advocacy group Reporters Without Borders, falling three places compared to the previous year.