The 64-year-old Hkun Htun Oo was arrested three years ago with other Shan State leaders who were peacefully advocating for political reform.
Currently serving a 93-year sentence in Putao prison in northern Kachin State, his health has seriously deteriorated in the past few months. He has long been suffering from diabetes and now has serious prostate problems, according to the statement from the Shan action groups.
The groups also said they were concerned with the health of other Shan State leaders, some of whom are serving sentences of up to 106 years in other prisons around Burma.
"One is in urgent need of surgery and another suffering mental illness. Already one of the detainees, 56-year-old U Myint Than, who had been in perfect health before his imprisonment, died in prison in Arakan State in May 2006 under suspicious circumstances," the statement said.
"A genuine federal union should be built on principles of justice and equality. Yet the regime, by imprisoning elected ethnic leaders and proceeding with its own coercive constitution-drafting process, has shown its complete contempt for these principles" said Sai Awn Tai, spokesperson of Shan Youth Power in Thailand, which is co-organizing the vigils.
The organizers are urging governments around the world to pressure Burma's military regime to immediately release Hkun Htun Oo, other Shan State leaders, and all political prisoners in Burma, including Daw Aung San Suu Kyi, and to immediately implement a nationwide ceasefire and begin dialogue with the opposition National League for Democracy and representatives of the ethnic nationalities.