The party of Myanmar democracy icon Aung San Suu Kyi released doves and balloons at a ceremony on Wednesday marking the 19th anniversary of an election victory that was voided by the ruling junta.
Around 300 people gathered at the headquarters of the National League for Democracy (NLD) in Yangon, as the trial of their leader on charges of breaching her house arrest continued at a notorious prison in the city.
Dozens of plainclothes security officials videotaped and photographed people entering the event, including some western diplomats, while security was boosted across the city, witnesses said.
The NLD won Myanmar's last democratic elections on May 27, 1990 by a landslide, but the military regime never allowed Nobel laureate Aung San Suu Kyi to form a government.
Wearing "Free Aung San Suu Kyi" T-shirts, senior party members released a total of 64 doves and balloons into the air -- symbolising her upcoming 64th birthday on June 19.
"We are releasing them to call for the release of Aung San Suu kyi and Tin Oo," an announcer said over a megaphone. Tin Oo is the detained deputy leader of the party.
Aung San Suu Kyi and Tin Oo have both been detained since May 30, 2003 following a deadly attack on her convoy during a party visit to northern Myanmar by an allegedly government-backed mob.
Authorities unexpectedly announced that Aung San Suu Kyi's house arrest had been lifted on Tuesday, a day before it was due to expire, but she remains in detention at Insein prison awaiting trial.
The 63-year-old faces up to five more years in jail on charges stemming from an incident in which an American man, John Yettaw, swam to her house earlier this month.
Diplomats from the United States, Britain, France, Italy and other western countries attended the ceremony.