Former Bosnian Serb leader Radovan Karadzic appeared before a U.N. war crimes judge for the first time on Thursday to answer genocide charges and said he had been kidnapped and feared for his life.

Karadzic, who was arrested last week after 11 years on the run, wore a dark suit and tie, and appeared gaunt, his trademark shock of hair whiter and shorter than when he was last seen in public out of disguise more than a decade ago.

Karadzic began in composed mood, giving one-word answers and occasionally cracking a wry joke. But as the proceedings continued he became more animated, then defiant.

Karadzic faces two charges of genocide over the 43-month siege of Sarajevo and the 1995 massacre of some 8,000 Muslims at Srebrenica, the worst atrocity in Europe since World War Two.

He said he would enter a plea after studying the charges. The case is due to resume on August 29.

The leader of Bosnian Serbs during the 1992-95 Bosnia war is the most prominent Balkan war crimes suspect arrested since late Serbian President Slobodan Milosevic, who died in detention in 2006 before his trial ended.

Karadzic said his arrest was illegal. "In Belgrade I was arrested irregularly, I was held kidnapped for three days. I had no right to a telephone call or even an SMS," he said.

He also attacked former U.S. Bosnian peace mediator Richard Holbrooke, saying: "If Holbrooke wants my death and regrets there is no death sentence at this court, I want to know if his arm is long enough to reach me here."

Holbrooke, architect of the peace deal which ended the Bosnian war, did not immediately comment.

At the start of the proceedings, judge Alphons Orie noted Karadzic was alone. Smiling, the suspect replied: "I have an invisible adviser but I have decided to represent myself."

Offered a chance to have the indictment read to him, Karadzic declined.

"I'm not interested in having someone else read an indictment to me. I would rather receive the new indictment that has been announced and sufficient time to study it, then have my initial appearance after that and enter my plea."

He appeared at the court after spending his first night in a cell at the U.N. war crimes tribunal detention centre in The Hague. He occasionally wiped his brow and spoke in Serbian.

SHAVEN

Since his arrest in Belgrade he has shorn the flowing beard and long hair that helped disguise him as an alternative healer in the years following the war. He was flown to the Netherlands on Wednesday morning.

Chief Prosecutor Serge Brammertz said he would conduct the trial efficiently, learning from the Milosevic case.

"Of course it will take some months before the prosecution and defence will be ready to start. It will be a complex trial but we are fully aware of the importance of being efficient," he told reporters.

Karadzic's lawyer in Serbia had said his client would make use of the 30-day-period he is allocated to make a plea. Under court rules if he refuses to enter a plea, then a plea of 'not guilty' is entered for him.

Karadzic's delivery to The Hague was key to Serbia securing closer ties with the European Union and his arrest was seen as a pro-Western signal by the new government sworn in this month.

France, the current EU president, said in a statement that Karadzic's arrest and transfer "mark an important step in the process of reconciliation in the western Balkans and in the rapprochement between Serbia and Europe."