UN war crimes judges on Thursday found former Bosnian Serb leader Radovan Karadzic guilty of genocide and sentenced him to 40 years in jail over the worst atrocities in Europe since World War II.

The court said Karadzic, the most high-profile figure convicted over the wars that tore Yugoslavia apart in the 1990s, bore criminal responsibility for murder and persecution in the Bosnian conflict.

Judge O-Gon Kwon said the court in The Hague found Karadzic guilty of genocide for the 1995 Srebrenica massacre and nine other charges of murder, persecution, and hostage-taking.

But in what will be a blow to thousands of victims, the court said it did not have enough evidence to prove "beyond reasonable doubt" that genocide had been committed in seven Bosnian towns and villages over two decades ago.

It marks the end of a marathon trial at the International Criminal Tribunal for the Former Yugoslavia for Karadzic's role during the 1992-1995 Bosnian war that claimed more than 100,000 lives and displaced 2.2 million others.

The 70-year-old listened stony-faced as Kwon said it was clear Karadzic bore "individual criminal responsibility" for murder, persecution as well as the hostage-taking of UN peacekeepers.

Karadzic "was at the apex of political, governmental and military structures" of the Bosnian Serb leadership and "at the forefront of developing and promoting its ideologies," Kwon said.


'Hugely significant'

"I hope this court will fulful its mission and put this man behind bars. Our children are dead," Munira Subasic, from the Mother's of Srebrenica, told AFP before the verdict.

"I hope finally the lies that have been told in Bosnia will be exposed," she added.

Karadzic, 70, is the highest-profile politician from the Balkans conflicts to be judged, after former Serbian strongman Slobodan Milosevic died in his prison cell while on trial in 2006.

UN rights chief Zeid Ra'ad Al Hussein hailed the verdict as "hugely significant".

The hearing, which has drawn more than 200 journalists and over 100 other diplomats and observers, took place amid tight security, with one police officer saying they were on "extra alert" following Tuesday's attacks in neighbouring Belgium.

Karadzic, as president of the breakaway Republika Srpska, was accused of taking part in a joint criminal scheme to "permanently remove Muslim and Bosnian Croat inhabitants... from areas claimed as Bosnian Serb territory".

This was done through a ruthless campaign of ethnic cleansing, indiscriminate killings, persecutions and terror.


Huge 'day for justice'

A long-time fugitive from justice until his arrest on a Belgrade bus in 2008, Karadzic, a one-time psychiatrist with his trademark bouffant hairdo, was found guilty for his role in the 1995 Srebrenica massacre in eastern Bosnia.

Almost 8,000 Muslim men and boys were slaughtered and their bodies dumped in mass graves by Bosnian Serb forces who brushed aside Dutch UN peacekeepers in the supposedly "safe area."

The massacre was the worst bloodshed on European soil since World War II.

He was also found guilty of being behind the 44-month siege of Sarajevo in which 10,000 civilians died in a relentless campaign of sniping and shelling.

"It’s a hugely significant day today for international justice," said Jasna Causevic, 58, one of the protesters outside the ICTY.

"Karadzic and his group, including Milosevic, divided Bosnia and that's still the case today," she told AFP.

In an unexpected earlier drama, the former spokeswoman for ex-chief prosecutor Carla del Ponte was detained at the tribunal by UN guards.

Florence Hartmann had been convicted of contempt and sentenced to seven days in jail for revealing confidential court details in a 2007 book.

During the trial, which open in 2009 and ended in October 2014 after an exhausting 497 days in the courtroom, some 115,000 pages of documentary evidence were presented along with 586 witnesses.

Lavien Partawie, 25, waiting outside the court with the Society for Threatened Peoples, said: "It is important for the victims of Bosnia Herzegovina. We are hoping to get justice."