By Aung Hla Tun
YANGON (Reuters) - Myanmar released 56 political prisoners on Tuesday in a presidential amnesty mainly for members of ethnic minority armies with which the government is seeking peace deals, activist and official sources said.
The release is the second since the country's reformist President Thein Sein made a promise during a trip to Britain in July that all prisoners of conscience would be freed by the end of the year. A total of 73 were released on July 23.
Thein Sein is attending a regional summit this week in Brunei.
The prisoners were set free on Tuesday from at least a dozen detention centres across the country, said a senior Home Ministry official, who declined to be identified because he was not authorised to talk to the media.
Myanmar's decades-long refusal to free activists, journalists, political opponents and even comedians and artists deemed threats to the army-run state were the main justification for years of Western sanctions on the country.
Under the junta, which ceded power in March 2011, the number of political prisoners was estimated to be as high as 2,500.
Hundreds of those have since been released under Thein Sein's quasi-civilian government and in response, most sanctions by the United States, Europe and Australia were suspended to allow the resumption of investment and development aid.
According to Bo Kyi of the Assistance Association of Political Prisoners (AAPP), a body that monitors prisoners of conscience held in Myanmar, most of those released on Tuesday were former members of either the Shan State Army or the Kachin Independence Army (KIA).
The two rebel groups are among about a dozen that for decades fought the central government in pursuit of greater autonomy in the mountains and jungles along the borders with China and Thailand.
To meet another condition to end sanctions, Thein Sein's government launched a complex and ambitious peace process in 2011. Though a preliminary peace agreement was made with the Shan group, the far stronger KIA has yet to come on board and conflict with the military is still going on.
Talks between a government delegation and the KIA were due to take place in the Kachin State capital, Myitkyina, on Tuesday. Previous rounds have all ended in stalemate.
Bo Kyi, who is also a member of a panel tasked with establishing which inmates were jailed for political reasons, said the AAPP's research had found Myanmar was still holding 133 political detainees and 232 activists were awaiting trial.
"We have asked the president for the unconditional release of all remaining political prisoners. I just don't know why he released only 56 today," said Bo Kyi, who was himself once a political prisoner.
(Additional reporting by Min Zayar Oo; Writing by Martin Petty; Editing by Robert Birsel)