(CNN) -- How bad is it to be a journalist in Eritrea? Even reporters who leave the Horn of Africa nation are fearful of talking about what happens there, according to Reporters Without Borders.

The group rated Eritrea as the world's worst place to be a journalist in its annual report on press freedom, issued Tuesday.

"Nobody knows about that country, because you can't report on what's going on there," said Clothilde Le Coz, the Washington director of Reporters Without Borders. Eritrean journalists who travel abroad won't talk, she said, because "they really fear for their lives."

The group's report offered a mixed view of how much freedom journalists had in 175 nations from September 1, 2008, through August 31, 2009, based on a 40-question survey completed by hundreds of media figures around the world.

It showed the Baltic Sea region as the best place for media freedom, with five of the top six nations on the list -- Denmark, Estonia, Finland, Norway and Sweden -- located there.

Conversely, Eritrea was rated the worst -- No. 175 -- slightly behind North Korea, Turkmenistan, Iran, Burma and Cuba.

The United States was rated No. 20, an improvement of 20 places over the previous year, with the report citing "Barack Obama's election as president and the fact that he has a less hawkish approach than his predecessor."

However, the report also noted continuing concern over the U.S. attitude toward the media in Iraq and Afghanistan. It said that "several journalists" were injured or arrested by the U.S. military, including Ibrahim Jassam, a Reuters cameraman and photographer held by U.S. forces in Iraq for more than a year.

Eritrea, which became independent with much fanfare 16 years ago, lacks an effective working media, with critics routinely jailed, according to Reporters Without Borders.

Le Coz called the nation -- in which fewer than 4 million people live in an area slightly larger than Pennsylvania -- the "largest worldwide prison for journalists," with 29 detained. China has 30 journalists in prison, she noted, but because it is so much larger with so many more people, "Eritrea is the worst one."

It was different in 1993, when Eritreans voted overwhelmingly for independence from neighboring Ethiopia after a long rebel war. Strategically located on the Red Sea flanking Ethiopia and Sudan, Eritrea was considered a possible bastion of Western-influenced democracy in the unstable region.

However, the People's Front for Democracy and Justice government has since banned opposition parties and held off adopting a constitution proposed in 1997 that would enhance political freedom.

Now the United States accuses Eritrea of arming and funding an Islamic extremist group trying to overthrow Somalia's transitional government.

The-CNN-Wire/Atlanta
TM & © 2009 Cable News Network, Inc., a Time Warner Company. All rights reserved.