Bo Kyi, a member of the Political Prisoner Scrutiny Committee, said about 50 political prisoners remained detained, while around 200 other people were still facing political charges that could see them jailed. More than 1,000 political prisoners had been previously freed under President Thein Sein's reformist government, which came to power in 2011 after almost five decades of military rule.
The continued detention of political prisoners in Myanmar has been a concern of the United States and other Western nations that want to promote the country's transition to democracy.
Myanmar is using the Southeast Asian Games, which run from Dec. 1-22, to showcase its transformation from international outcast to fledgling democracy.