International media watchdog Reporters Without Borders says East Asia is the toughest part of the world for journalists to carry out their jobs.
The media in China cannot operate freely, the group says
Publishing its 2005 World Press Freedom Index, the organisation lists North Korea as the very worst in the world, bottom of the list of 167 countries.
The group says North Korea is a black hole for news, where private media and freedom of expression do not exist.
China, Burma and Vietnam are also ranked among the 10 worst nations.
In North Korea, the secret police continue to hound those listening to foreign radio stations and there are reports of journalists being held in labour camps for professional errors or deviating from the official line, Reporters Without Borders says.
The Paris-based organisation says Chinese journalists are routinely forbidden from mentioning many sensitive subjects.
167. North Korea
In Burma, hopes for the release from prison of pro-opposition journalists have come to nothing and censorship is routine, although the situation in Vietnam improved slightly with no journalists known to be in prison.
In Thailand, press freedom has deteriorated sharply. The country is now ranked 107th, down from 59th last year, and falls behind Indonesia.
Reporters Without Borders says violence in the majority-Muslim south of the country is one reason for the change.
The other is the attitude of Prime Minister Thaksin Shinawatra, who has launched a number of law suits against journalists and is blamed for closing down radio and television shows critical of his administration.