UN prosecutors said yesterday they plan to file a new indictment against Radovan Karadzic within days to update the eight-year-old charges against the former Bosnian Serb leader.

Prosecutor Alan Tieger told a Yugoslav war crimes tribunal hearing he will file a motion seeking permission to update Karadzic's 11-count indictment by Monday.

Tieger did not indicate whether the new indictment would include more charges than the 25-page indictment.

Karadzic, 63, faces genocide charges for allegedly masterminding atrocities, including the slaughter of more than 8000 Bosnian Muslims in Srebrenica in July 1995 and the siege of Sarajevo, when he was president of the break-away Bosnian Serb republic.

Judge Iain Bonomy registered not guilty pleas to the 11 charges last month after Karadzic twice refused to enter pleas.

At yesterday's hearing Karadzic said he had launched an investigation to back his claim that he was promised immunity from prosecution in return for disappearing from the public eye in a 1996 deal with US peace envoy Richard Holbrooke - a claim Holbrooke has denied. Karadzic said that when tribunal officials blocked attempts to shield him from prosecution Nato tried to kill him.

"I have irrefutable evidence that Nato tried to liquidate me," he told Bonomy. He did not elaborate.

Karadzic was arrested in July after 13 years on the run.

Yesterday, he insisted he would conduct his own defence. "I have to hold the reins of my defence in my own hands," he told Bonomy.