Sixty-six journalists were killed worldwide in 2011, many of them covering Arab revolutions, gang crime in Mexico or political turmoil in Pakistan, Reporters Without Borders (RSF) said on Thursday.
Ten journalists were killed in Pakistan, most of them murdered, making it the most dangerous country for news coverage for the second year running.
With pro-democracy demonstrations prompting violent reprisals from Arab governments, the number of reporters killed in the Middle East doubled to 20 this year.
A similar number were killed in Latin America, where criminal violence was rife, the Paris-based RSF said in a statement.
Some 1,044 journalists were arrested this year - nearly double the 2010 figure - due largely to the Arab Spring, as well as street protests in countries including Greece, Belarus, Uganda, Chile and the United States.
"From Cairo's Tahrir Square to Khuzdar in southwestern Pakistan, from Mogadishu to the cities of the Philippines, the risks of working as a journalist at times of political instability were highlighted more than ever in 2011," RSF said.
China, Iran and Eritrea remained the biggest prisons for the media, it said, without specifying how many journalists were in jail there.
The 10 locations that RSF considered the most dangerous for journalists included Abidjan, the business capital of Ivory Coast, where at least two reporters were killed in electoral violence, and Cairo's Tahrir Square, where journalists were systematically attacked by supporters of Egyptian president Hosni Mubarak before he stepped down in February.
The Arab Spring flashpoints of Deraa, Homs and Damascus in Syria, Change Square in the Yemeni capital Sanaa, and the Libyan rebel stronghold of Misrata were also on the list.
Last year 57 journalists were killed for their work the world over. The worst year of the past decade for journalists was 2007, when war in Iraq pushed the global toll up to 87.