Repressive regimes are increasingly highlighting blogs and websites as a threat to be shut down or censored, according to the annual report (PDF 1.36MB) from Reporters Without Borders (RSF) published for World Press Freedom Day.

The report said that websites, personal web pages and blogs in some countries have become the only source of opposition or independent news.

But the censors are watching and preventing access to such sites, and routinely filter, monitor or delete material they consider inappropriate.

China is the most prolific censor by far but other countries are fast catching up, according to the press freedom organisation.

"Without making any comparison with the harsh restrictions in China, the internet rules recently adopted by the European Union are very disturbing," said Julien Pain, head of the internet freedom desk at RSF.

"One of them, requiring ISPs to retain records of customers' online activity, is presently being considered in Brussels and seriously undermines internet users' rights to online privacy."

The sitting president in Belarus shut down the opposition's website for the duration of the elections, according to RSF, while website users in Burma are logged every five minutes and web email is blocked from entering the country.

RSF claimed that Malaysia is cracking down on bloggers, and that four people were arrested in the Maldives for setting up an internet newsletter.

The report highlighted British company Cable & Wireless, which has shares in an associate company which controls all internet access in the Maldives.

North Korea gets the RSF award for most repressive regime. Internet access is restricted to a few thousand of the party elite, according to RSF, and even then is heavily censored and includes 30 sites praising the regime.

Among these sites is www.uriminzokkiri.com, which has photos and adulation of the 'Dear Leader' Kim Jong-Il and his late father Kim Il Sung.

"The US is also far from being a model in regulation of the internet," said Pain. "The authorities are sending an ambiguous message to the international community by making it easier to legally intercept online traffic and by filtering the internet in public libraries."

The report also criticises the conduct of western companies that aid and abet censorship. Yahoo, Microsoft and Cisco are accused of " throwing doubt on the US commitment to freedom of expression".