Amnesty International said on Tuesday that King Abdullah II's decision to release 116 activists arrested during violent protests last month against fuel price hikes was "too little, too late."
"This stifling of political dissent is entirely unacceptable and though we are pleased 116 people are to be set free, unless this means there are wider human rights reforms planned then it really is too little, too late," said Ann Harrison, Amnesty deputy director for the Middle East and North Africa.
The state security court on Tuesday ordered the release of 56 activists, a day after the king instructed the government to free them and a second group of detainees is expected to be set free on Wednesday.
But 13 people accused of vandalism, theft and assaulting policemen are expected to remain in jail, a judicial official said.
"There are 13 individuals who are not being released under this royal decree. We are seeking assurances that they are not being held to punish them for legitimate protest, not being subjected to ill treatment and given a fair hearing according to international standards," Harrison said in a statement.
"There is a danger King Abdullah's announcement will be seen as nothing more than a PR exercise because the reality is that dozens of people in 2012 have been detained solely for peacefully calling for economic and political reforms."
Three people were killed, including two policemen who were shot, and more than 70 injured in violent protests against a government decision on 13 November to raise fuel prices by up to 53 percent, according to police.
Amnesty also called for "prompt, thorough and independent investigations into claims that those held had been subject to beatings, denied adequate medical treatment and refused access to lawyers and family members."
"The Jordanian authorities also must stop prosecuting people before the state security court which is presided over by judges a majority of whom are from the armed forces and where proceedings fall short of international standards for fair trials," it added.