The United States says it is “deeply concerned” about the Ethiopian government's conviction of 24 people, including several journalists and opposition members, on terrorism related charges.

Journalist Eskinder Nega and opposition member Andualem Arage were among those found guilty Wednesday of charges including the encouragement of terrorism and high treason.

The men, 16 of whom were convicted in absentia, could face life in prison under Ethiopia's harsh anti-terror legislation. But prosecutors on Wednesday suggested jail terms of five years to life when they are sentenced next month.

State Department Victoria Nuland said in a statement such convictions raise “serious questions” about the intent of Ethiopia's anti-terror laws, which critics say are used to stifle dissent.

Rights group Amnesty International also condemned the conviction, saying the men were found guilty on “trumped up” charges.” The group said freedom of expression is being “systematically destroyed by a government targeting any dissenting voice.”

The defendants were accused of having ties to an outlawed political party called Ginbot Seven, which the government has labelled a terrorist group. Some were also accused of trying to incite unrest by writing about the anti-government protests that swept North Africa last year.

Ethiopia's government has denied using anti-terror laws passed in 2009 to clamp down on opposition figures and journalists, saying their arrests have nothing to do with their reporting or political affiliations.

Rights groups say more than 150 opposition politicians and supporters have been detained since last year on terrorism-related charges.