Dec 10, 2007 (AFP), Military-ruled Burma has stepped up its offensive against ethnic Karen rebels following a crackdown on pro-democracy protests in September, one of the main insurgent groups said Monday.

The Karen National Union (KNU) said that Burma’s military began the offensive about one year ago, but that the attacks have intensified since October.

The KNU accused the State Peace and Development Council (SPDC) of waging a "genocidal war" against ethnic Karen villagers, saying thousands of people have had to flee their homes to escape the fighting.

"In the offensives, the SPDC army troops … perpetrate the heinous crimes of arresting and killing innocent Karen civilians, plunder, destruction, forced relocation, forced labor and extortion of money," the KNU said in a statement.

"The current military campaign is in fact a genocidal war and it is diametrically opposed to the process of resolving the political problems by political means," it said.

The KNU is the largest rebel group fighting Burma’s armed forces and one of the few remaining ethnic insurgent groups yet to sign a peace deal with the junta.

Burma, under military rule since 1962, has signed ceasefires with 17 other ethnic armed groups.

The latest military onslaught began after soldiers and police violently suppressed pro-democracy protests in the main city of Rangoon and other towns across the country.

The protests, led by Buddhist monks, were the biggest threat to military rule in nearly 20 years.

A UN report said Friday that at least 31 were killed and 74 missing after the crackdown, with more than 600 dissidents still in detention.