Former Bosnian Serb military chief Ratko Mladic has arrived in the UN detention unit in the Hague in the Netherlands to face war crimes charges.

Mladic is accused of orchestrating the 43-month siege of the Bosnian capital Sarajevo in which 10,000 civilians were killed and the massacre of 8,000 Muslim men and boys from the town of Srebrenica in July 1995.

A panel of judges will be appointed and Mladic must appear in court 'without delay'. It is considered more likely to happen on Thursday or Friday.

At his initial court appearance, the indictment will be read to Mladic and he will be asked to enter a plea. If he pleads guilty, judges will set a date for sentencing.

If he pleads not guilty, a pre-trial judge will be appointed and regular status conferences will be held to discuss pre-trial issues. During this time the indictment can also be amended.

The court, due to complete its work in 2014, has been criticised for lengthy trials which often last several years, and judges have urged prosecutors to shorten former Bosnian Serb leader Radovan Karadzic's indictment.

Mladic was indicted in 1995 together with Karadzic. Prosecutors initially wanted to try both men together but split the case shortly before Karadzic's trial started.

Frederick Swinnen, special adviser to chief prosecutor Serge Brammertz, said it was too early to say whether the Mladic and Karadzic cases would be reunited, but noted that doing this would delay the trial of Karadzic.

If convicted, Mladic would stay in the court's detention unit until the tribunal president selects one of the states from the tribunal's list of where Mladic will serve his sentence.

Earlier today, Serbian judges rejected Mladic's appeal against a transfer to the UN-backed ICTY to stand trial for alleged atrocities committed during the 1992-95 Bosnian war.

Europe's most wanted man was arrested in the village of Lazarevo in northeast Serbia on Thursday after almost 16 years on the run.

Mladic's son, Darko, has said his father insists 'he had nothing to do with' the Srebrenica massacre, and had in fact saved lives.

Earlier today, Mladic paid a visit to the grave of his daughter Ana, who committed suicide aged 23, reportedly because of the accusations against her father.

The retired general was taken under police guard to the Topcidersko cemetery in Belgrade and later returned to his detention cell, before being put on a plane to the Netherlands.

Meanwhile, thousands of Bosnian Serbs rallied today to show support for former general Ratko Mladic, who was flown to a UN court to face genocide and war crimes charges.

Police said up to 10,000 protesters gathered in Banja Luka, the capital of the Bosnia Serb entity Republika Srpska, to decry Mladic's arrest in Serbia last week and hail him as 'brave son.'