Burma's longest-serving political prisoner, who was freed Tuesday after 19 years behind bars, vows to continue pressing for freedom from the junta's 46 years of military rule.

Win Tin, 78, a journalist-turned-activist who helped found Aung San Suu Kyi's opposition party in 1988, was one of at least seven political prisoners released, according to Amnesty International. There are still an estimated 2,100 political prisoners held in Burma, the rights group said.