The leaders of China, Russia and Rwanda are among the worst "predators of press freedom" according to Reporters Without Borders.
The annual report from the Paris-based Reporters Without Borders, published to mark World Media Freedom Day, highlights the worst offenders of media censorship and violence.
The list contains political figures as well as religious leaders, militias and criminal organizations.
A number of world leaders are on the list. Gilles Lordet, director of research at the media watchdog, says one of the worst offenders is President Paul Kagame of Rwanda, where an election is to take place in August.
"He does not respect the work of the journalists, he does not want to have press freedom in his country and he is pressuring and he can be very intimidating with journalists and censoring very regularly media and press that do not share his point of view," Lordet said.
New additions to the list included Chechen President Ramzan Kadyrov and Yemeni President Ali Abdulah Saleh. Lordet says media rights in Yemen are rapidly eroding.
"Since May 2009 we observed a very bad evolution, with a lot of trial, with a lot of journalists in prison, a lot of journalists harassed and it is really the worst evolution of media freedom in the world," Lordet said.
Another new addition to the list was Taliban leader Mullah Omar.
"It is important sometimes to really point at an individual like with Mullah Omar because he has really an influence on his group. Sometimes we can really identify one man, one person, who concentrates the reason that there is so much violence against journalists," Lordet said.
Some names have been dropped from last year's list. A number of Iraqi Islamist groups were taken off. Reporters Without Borders says violence remains high but journalists are no longer a specific target.
But overall, says Lordet, the picture has not changed much from last year.
"If we compare the list with last year, we think on a global scale there is no improvement. There [are] still the same predators, there [are] still the same countries where the situation is very bad," Lordet said.
In Mexico, named as one of the most dangerous countries for the media, 62 journalists have been killed in the past 10 years.
The Philippines were also highlighted as a particularly dangerous place for journalists: 30 were killed in a single attack by gunman last November.
News
Reporters Without Borders Names World's Worst Media 'Predators'
Leaders of China, Russia and Rwanda top list; Chechen, Yemeni presidents new additions