YANGON (AFP) - Myanmar released dozens of political prisoners on Wednesday, including one of its most famous comedians, in a tentative sign of change in the authoritarian state after decades of repression. But rights groups criticised the hugely anticipated amnesty as insufficient as the regime kept most of its roughly 2,000 political detainees - including democracy campaigners, journalists, monks and lawyers - locked up. "We are still compiling the list but as far as we have confirmed 184 political prisoners have been released," said Kyi Toe, a member of opposition leader Aung San Suu Kyi's National League for Democracy (NLD) party. "About 100 were NLD members," he added. The prominent satirist and vocal government critic Zarganar, who goes by one name, was among those released as part of a pardon of more than 6,300 prisoners by the new nominally civilian leadership. The dissident was arrested in 2008 after organising deliveries of aid to victims of Cyclone Nargis - which left 138,000 people dead or missing - and sentenced to 59 years' imprisonment, later reduced to 35 years. Asked after he arrived back in Yangon if he had a message for Myanmar's leader, Zarganar replied: "I would like to ask him why he is so stingy. There are many people still in prison to be released." According to the Thailand-based Assistance Association for Political Prisoners, the regime also released General Hso Ten, a prominent ethnic Shan leader sentenced to 106 years for charges including high treason. But it said many leading dissidents, including key figures involved in a failed 1988 student-led uprising, were apparently kept behind bars. Many political prisoners were sentenced to decades in jail and have endured "torture and other forms of cruel, inhuman or degrading treatment", according to Amnesty International, which urged the regime to go further. "Today's amnesty does not distinguish Myanmar's new government from its previous military government," said Benjamin Zawacki, a researcher at the rights group. "If Myanmar's authorities are serious about demonstrating their commitment to reform, this must be only the first step towards a release of all political prisoners as soon as possible," he added. A mass pardon of dissidents would arguably be the clearest sign yet of change under a new government that has reached out to critics including pro-democracy leader Aung San Suu Kyi, who was freed in November. State media announced Tuesday that more than 6,300 elderly, sick, disabled or well-behaved prisoners would be granted an amnesty from Wednesday "on humanitarian grounds", raising hopes hundreds of dissidents would walk free. President Thein Sein, a former general and senior junta figure, has surprised critics by signalling a series of political reforms since taking power following a controversial election last November. He has been applauded by international observers for holding direct talks with Suu Kyi, who spent most of the past two decades locked up by the junta. In a rare concession to public opinion in the authoritarian nation, the government last month suspended construction of a controversial mega-dam, risking the anger of traditional ally China, which is backing the project. A top US official, Kurt Campbell, on Monday hailed "dramatic developments" in Myanmar including what he described as "very consequential dialogue" between the Nobel Peace Prize winner and the leadership. He hinted that concrete moves towards democracy by Myanmar could lead to an easing of sanctions. "We will match their steps with comparable steps," he said. Suu Kyi, whose party won 1990 elections but was never allowed to take power, has said she believes Thein Sein genuinely wants to carry out reforms, but cautioned it was too soon to say whether he would succeed. He is widely believed to face resistance to change from hardliners in the regime, and sceptics argue that the steps announced so far could easily be reversed and the dissidents re-arrested. "For decades there's been a revolving door in and out of Burma's prisons for many political activists," said Elaine Pearson, deputy Asia director at Human Rights Watch. "The real test will be whether the government stops putting people in prison for speaking their minds and criticising the government or military."