The New Light of Myanmar, a newspaper published by the country's Interior Ministry, reported that the government granted amnesty to 514 prisoners, including some foreigners, "on humanitarian grounds."
British Foreign Minister William Hague described the measure as another step on Myanmar's road to democracy. He added, however, that London has consistently called for the release of "all political prisoners" in the country.
The Assistance Association for Political Prisoners in Myanmar published the names of 86 individuals it said were political prisoners released under the amnesty program.
The European Commission this week backed a proposal to extend preferential trade arrangements to Myanmar in recognition of the country's political reforms. The country moved a step closer to democracy beginning with general elections in 2010.
Italian Foreign Minister Giulio Terzi said in a statement that he wanted the international community to "continue its efforts to foster reform in the country while vigilantly monitoring the reforms undertaken by Myanmar."
Terzi was the first European official to visit Myanmar after the European Union suspended sanctions on the country in April.