Freedom for political prisoners is a benchmark used by Western nations critical of Myanmar's former military regime to judge Thein Sein's administration. Previous releases have been a major factor in decisions by those nations to ease economic and political embargoes they placed on the previous government for its poor human rights record and undemocratic rule.
Thein Sein had served with the old regime, but came to office last year after a general election. He began a series of democratic reforms and opened a dialogue with the country's pro-democracy movement, winning Suu Kyi's praise for his efforts. She agreed to have her party contest by-elections in April, and she and other colleagues are now members of the small opposition faction in the military-dominated legislature.
Human Rights Watch says at least 659 political prisoners have been released over the past year. Estimates by human rights groups of the number remaining in custody range from about 200 to about 600. Suu Kyi's National League for Democracy party says the number is 330.
"We will call for the release of all 330 political prisoners," Suu Kyi, the country's most famous former political detainee, told a news conference Tuesday. It was her first public appearance since returning from a high-profile two-week tour of Europe, her first trip abroad in 24 years.
The state-run New Light of Myanmar newspaper reported that 37 men and nine women were being freed.
It said the decision had been made on humanitarian grounds "with a view to ensuring the stability of the state and making eternal peace (and) national reconciliation."
"We are very happy that our fellow political prisoners are being released," Ko Ko Gyi, a prominent former political detainee, told The Associated Press. "However, we will continue to work for the release of all political prisoners."
Suu Kyi received a hero's welcome during her European journey, but was criticized by Myanmar authorities for calling her homeland Burma during the trip. The election commission, which oversees laws pertaining to political parties, said Suu Kyi should stop using the name and "respect the constitution."
Opposition activists have long referred to the Southeast Asian nation as Burma to protest against the former army junta, which held absolute power and changed the country's English name to Myanmar in 1989.
Suu Kyi retorted Tuesday that the junta had altered the name two decades ago "without consulting any public opinion." Suu Kyi was under house arrest at the time and said she heard the news over the radio.
"They shouldn't have done it like that," Suu Kyi said. "All these issues are concerned with the basic principles of democracy ... and as I believe in democratic values, I think I can use whatever term I want."
In the official state language, the country and its people are both pronounced Myanmar, and the distinction between the names exists in English but not the local language.
The former junta, which ceded power last year, justified the name change on the ground that the word Myanmar better reflects the country's ethnic diversity. The term Burma connotes Burman, the dominant ethnic group in the country, to the exclusion of ethnic minorities. But regime opponents and exile groups from a range of ethnicities as well as foreign governments including the United States have persisted in calling the country Burma in protest against an undemocratic regime they long saw as illegitimate.