The Committee to Protect Journalists has expressed concern about the treason trial of 14 Ethiopian journalists and dozens of opposition leaders.
In a statement issued this week, the international group said initial legal proceedings have reinforced concerns that the defendants may not get a fair trial.
The journalists have been jailed since November, and have been denied bail. They are charged with "outrage against the constitution" and "genocide," which could result in sentences of death or life imprisonment.
Ethiopia's government has accused the journalists and dozens of opposition figures and activists of trying to overthrow the government.
Prosecutors say the defendants conspired with an Eritrean-backed rebel group to stage a coup.
The Committee to Protect Journalists says it will be watching the proceedings very closely, and has called for the journalists to be released immediately.
Five VOA journalists were among those charged with treason in absentia. The Ethiopian government recently dropped charges against them.