A total of 21 journalists and six netizens and citizen journalists have been killed so far this year, according to Reporters Without Borders (RSF), which claims this equals "a rate of one news provider killed every five days".
To mark World Press Freedom Day, the press freedom group has also released "an updated list of its 'predators of the freedom to inform'", with six new entries contributing to a total of 41 "predators".
"What with crackdowns on protest in Arab countries, and suppression of political opposition, criticism and reporting in other parts of the world, the first four months of 2012 were especially violent for those who try to provide news and information," RSF reports.
The UN secretary-general Ban Ki-moon and the director-general of UNESCO Irina Bokova also issued a joint statement for World Press Freedom Day in which they described freedom of expression as "one of our most precious rights".
"It underpins every other freedom and provides a foundation for human dignity. Free, pluralistic and independent media is essential for its exercise.
"This is the message of World Press Freedom Day. Media freedom entails the freedom to hold opinions and to seek, receive and impart information and ideas through any media and regardless of frontiers, as stated in Article 19 of the Universal Declaration of Human Rights. This freedom is essential for healthy and vibrant societies."
Referring to changes within the Arab world, the statements adds that "newfound media freedom" in these regions "is promising to transform societies through greater transparency and accountability".
"It is opening new ways to communicate and to share information and knowledge. Powerful new voices are rising — especially from young people — where they were silent before."
But there remain "severe pressures" for media freedom globally, the statement adds.
"Last year, UNESCO condemned the killing of 62 journalists who died as a result of their work. These journalists must not be forgotten and these crimes should not remain unpunished.
"As media moves online, more online journalists, including bloggers, are being harassed, attacked, and killed for their work. They must receive the same protection as traditional media workers.
"... World Press Freedom Day is our opportunity to raise the flag in the fight to advance media freedom. We call on States, professional media and non-governmental organisations everywhere to join forces with the United Nations to promote online and offline freedom of expression in accordance with internationally accepted principles.
"This is a pillar of individual rights, a foundation for healthy societies and a force for social transformation."
On Wednesday (2 May) the Committee to Protect Journalists released its "most censored countries" list, which was topped by Eritrea.