Former Bosnian Serb leader Radovan Karadzic again boycotted his own war crimes trial at The Hague on Monday but pledged in a letter to judges that he would attend a procedural hearing Tuesday on his defence.

The trial has proceeded without him, with United Nations prosecutor Alan Tieger winding up his opening statement Monday before judges at the International Criminal Tribunal for the Former Yugoslavia.

Tieger called the July 1995 slaying of 8,000 Muslim men and boys in Srebrenica "one of humanity's dark chapters" and laid the blame squarely at Karadzic's feet.

"These crimes were the culmination of the accused's determination to cleanse eastern Bosnia to ensure the Serb state he envisioned," Tieger said.

Karadzic, 64, is charged with two counts of genocide and nine other crimes against humanity and war crimes linked to atrocities throughout the 1992-95 war in Bosnia-Herzegovina.

He is representing himself but has refused to enter pleas — although he insists he is innocent. If convicted, he faces a maximum sentence of life imprisonment.

Karadzic's boycott of the trial last week frustrated dozens of war survivors — many of them widows from Srebrenica — who had travelled hundreds of kilometres by bus to see the man who is accused of masterminding Europe's worst atrocity since the Second World War.

Karadzic wrote to judges that he would attend Tuesday's hearing to help find "a solution which will lead to not only an expeditious trial but a fair one."

He was arrested 14 months ago on a bus in Serbia's capital, Belgrade, disguised as a New Age healer.

With files from The Associated Press