War crimes suspect Radovan Karadzic arrived in the Netherlands on Wednesday to face trial at The Hague on charges of genocide for his actions in the 1992-95 Bosnia war.

The former leader of the Bosnian Serbs is being held at a nearby detention centre and is expected to appear at the UN war crimes tribunal on July 31.

The plane carrying Karadzic landed at Rotterdam airport. Karadzic faces two charges of genocide for 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.

Arrested last week after 11 years on the run, Karadzic was most recently living under an assumed name as a bearded, long-haired alternative healer.

Earlier in Belgrade, he was escorted to the airport by masked officials from the Serbian secret service. A convoy of black jeeps took him from prison to the capital's airport.

On Tuesday, some 10,000 hardline nationalists, many brought by bus from rural nationalist strongholds, showed their support for him in downtown Belgrade, chanting his name and holding up giant banners with his picture.

Clashes broke out when several dozen youths linked to hooligan groups threw flares, stones and garbage cans at riot police. Some 45 people, most of them policemen, were wounded.

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

Sending him to The Hague is expected by the government to defuse tension and stop further protests, but also to unlock EU trade benefits.

Karadzic's legal team had tried to delay his extradition by launching a cumbersome appeal procedure that threatened to drag on for several more days. But even they admitted they could only postpone, not stop his transfer.

Relatives have said Karadzic is in good spirits and preparing for his defence. - Reuters