The inclusion of the US in this list - compiled by the Committee to Protect Journalists - underlines the importance of vigilance in preserving press freedom even in places where it is much celebrated, observers say. It is in recognition of this need to safeguard the media that today has been marked World Press Freedom Day.

Hong Kong's press is widely viewed as free and vibrant but every year, something happens to raise concern over attacks on its independence, perceived or otherwise. The media has long been criticised for being irresponsible and sensational in a bid to increase readership.

Doreen Weisenhaus, director of the Media Law Project at the University of Hong Kong, says the legacy of a 'secretive government' - inherited from the colonial administration - has left the media struggling for information and feeling 'uncomfortable' at any sign of a curtailment of freedoms.

'We have no freedom of information act and the media is often flailing against the system to get information,' she says, citing the Tsim Sha Tsui shootout between three policemen as one example of rampant media speculation as a result of official secrecy. 'The media is not seen as an equal partner by the government - there is not that respect for them. There is constant criticism of the credibility of the press as it struggles to do reporting.'

Professor Weisenhaus says that such 'handcuffs' on an otherwise free and robust press cause issues such as the public service broadcasting review to be of great concern to journalists.

Lo King-wah, of the press freedom subcommittee of the Hong Kong Journalists Association, says the review should be watched closely because of 'a lot of major media organisations in Hong Kong are controlled by big corporations and big tycoons'.

'The media could be easily influenced by commercial interests and that is why an independent public broadcaster such as RTHK, which has real editorial independence, is needed to keep a balance,' he says. 'The media as a watchdog is very important here since we do not have a fully democratic system of government.'

Professor Weisenhaus says that because the media has such a unique role in Hong Kong, where the executive head and much of the legislature are not directly elected, it deserves more leeway from the government.

'[The media is] in part to represent the interests of the public, which cannot act as it would if there was full democracy here,' she says. 'Hong Kong is not ready for restrictions, like a statutory press commission, because the checks and balances don't exist here like they would in a full democracy. You have to allow more freedom for the press to operate when you don't have the other legal infrastructure in place.'

She says proposals such as the Law Reform Commission's recent recommendations to include the media in criminalising infringement of privacy through covert surveillance were thoroughly unsuitable for Hong Kong because the city lacked such protection.

Bob Dietz, Asia programme co-ordinator of the Committee to Protect Journalists, agrees that the 'somewhat concentrated' media ownership here is a concern, but says Hong Kong's fight is more one of preservation. 'It is a fragile thing - press freedom,' he says. 'It is a government attitude, it's public expectations. In Hong Kong, every time an issue comes up, people are right to look at it closely and watch it carefully.'

The Hong Kong media's counterparts across the border are fighting for press freedom on another scale. Any hopes that President Hu Jintao's administration would take a more open policy towards the media have been dashed and many media watchers believe this trend will continue.

'The attitude towards journalists and press freedom has become quite heavy-handed since Hu took power,' Mr Dietz says. 'When Beijing was selected as host city for the Olympics, there was a lot of talk about press freedom and how they would allow open access for the media ... we are concerned that promise is going to be very difficult for China to deliver on. We are going to address that to the International Olympic Committee.'

Mainland journalists, frustrated by restrictions they face in print or broadcast, are turning to the internet, Mr Dietz says. Of the 32 journalists detained in China as of December, 15 are being held for internet-related activities. Of these, dissidents claim at least four were arrested with help from internet company Yahoo, which provided information about the journalists' identity at the government's request.

'The role of US internet companies in undermining press freedom in China is a big issue in other countries too,' Mr Dietz says. 'When someone gets thrown in jail for expressing something online or in print, people become concerned. It's something these companies are embarrassed by, but they have such a big growth market in China that they cannot back away in the name of human rights issues. We, and consumers, are going to have to continue to put pressure on them.'

Despite the shutdown of newspapers, the detention of journalists, and news blackouts on important public health, rights and political issues, there are strong forces moving in the opposite direction, Mr Dietz says.

'Journalists in China know they are under pressure and there are rules to follow, but there is the market factor - papers have to turn a profit and people are going to be competing for better stories,' he says. 'As China's economy expands, the growing middle class has higher expectations of journalists. I see the drive coming from the consumers who want better information, be it economic or political. We see these factors as really putting pressure on the government to improve the situation.'

Another strong force bearing down on the government is the emboldening of journalists themselves. Mr Lo says instances of journalists on the mainland 'standing up to defend themselves' are inspiring.

In one case, a senior editor with the China Youth Daily, Li Datong , posted a letter on the paper's computer system attacking the Communist Party and the editor-in-chief's plan for an appraisal system in which bonuses are linked to praise or criticism by party leaders.

By the time the letter was removed from the site, it had spread to some of the country's most popular internet forums and was being e-mailed at blinding speed. The government tried to order sites to remove the letter, but two days later admitted defeat and the appraisal plan was scrapped.

'The Freezing Point supplement of the China Youth Daily was also shut down for political reasons but because of public pressure, they had to reverse the ban,' Mr Lo says. 'We are very disappointed with Hu Jintao's eagerness to control the press, but there is a brighter side - that people are more willing to speak their mind.'

Ms Weisenhaus says many mainland journalists are testing the limits. 'They know what it is they're striving for,' she says. 'If one door is closed, they try another - what you don't see is them giving up. There is a dogged determination to continue, a pressure to be more creative and an unbelievable optimism and dedication to practise good journalism.'