A top leader of the Burma's rebel Karen National Union (KNU), Pado Manh Sha, 65, was assassinated at his home in Mae Sot district yesterday (Feb 14).

Pado Manh Sha was the KNU secretary general and an outspoken critic of Burma's military government.

Colonel Passawat Teangjui said the man was killed yesterday afternoon at his home by three gunmen believed to be ethnic Karen.

"His relatives who witnessed the killing said the first man went up to greet Pado Manh Sha while he was resting, but then shot him once. A second man came up and shot him again," Passawat said.

Agence France-Presse quoted Win Min, a Thailand-based Burma analyst, describing the death as a major loss for the KNU.

"He is one of the top leaders for the group. He is an articulate strategist and a unifying figure for the KNU," Win Min said.

Another Burma analyst said the killing may have been the result of factional fighting within the KNU. But if it was done on behalf of Burma's junta--which is not known to carry out political assassinations across the border--it would be "a different picture and would send a chill down the spine of the pro-democracy groups and leaders, because Manh Sha was also a leader of that movement".

KNU is one of the last remaining rebel armies. It has refused to put down its arms, although the group has entered into off-and-on negotiations with the Rangoon government over the years.

KNU suffered a setback in 1994 when a major Buddhist faction broke off and allied itself with Rangoon, and later set up the Democratic Karen Buddhist Army (DKBA). Combined forces of DKBA and Burmese government troops delivered another blow to the KNU in 1995 when they forced the rebel group to flee their Manerplaw headquarters.

DKBA is largely seen as a Rangoon proxy and has often engaged in battles with Thai soldiers along the border.

KNU and Rangoon entered into another round of peace talks in 2004 at the insistence of the Thai government, but the ceasefire did not last very long.

Aung Naing Oo, an exiled Burmese analyst, was quoted saying one of the biggest concerns along the border now was that more assassinations might follow.

Throughout his career as a rebel commander, Manh Sha worked closely with the late General Bo Mya, who died in December 2006 from natural causes.

Until his death, Bo Mya dominated much of KNU politics and its military campaign. After 24 years leading the KNU, Bo Mya decided to step down to end an internal rift. Another ageing leader, Ba Thin Sein, 81, replaced him in 2000.

With reports from Nirmal Ghosh (The Straits Times)