Hariri was killed in a car bombing in Beirut. Twenty-two other people also died in the explosion. Hariri's murder sparked a worldwide outcry and some anti-Syrian Lebanese politicians have said Syria was behind the bombing, a charge Damascus denies.

The opening ceremony, attended by UN officials and diplomats, was held at a former gymnasium at the headquarters of the Dutch intelligence service, where the court will sit. It is expected the tribunal will take about three to five years to hear the case and a budget of just over 40 million euros has been allocated for its operations in 2009.

The tribunal was created by a 2007 UN Security Council resolution and will apply Lebanese law. It has an initial, renewable, three-year mandate. The identities of its 11 judges, four of them Lebanese, are being kept secret.

World's first anti-terrorist court
The chief prosecutor, Canadian Daniel Bellemare, said that the new tribunal constitutes the world's first anti-terrorist court.

"By the very nature of its mandate, the STL is the first international anti-terrorist tribunal,"
he told reporters. He said the court was set up not to seek revenge, but "a justice that ensures everybody is treated with dignity and respect."

Mr Bellemare said that despite the rejection of an earlier appeal, he will seek the extradition of four generals from Lebanon. The four men were commanders of Lebanon's pro-Syria security establishment at the time of the killing and are currently in prison in Beirut. Mr Bellemare said he would continue to gather evidence and may file several indictments during the process:
"As soon as I think I have enough evidence against someone or a group of persons, I will present an indictment."

Here for the victims
Robin Vincent, the registrar of the tribunal, told the audience at the ceremony, that "In the end we are not here for the United Nations, nor are we here for the international community. We are not here for the perpetrators of crime but for the victims."

Suspects transferred to The Hague will be kept at the Scheveningen detention centre, which also houses suspects of the International Criminal Court and the International Criminal Tribunal for the former Yugoslavia. If indictments are issued, suspects can surrender to the tribunal voluntarily, or the tribunal can ask the Security Council to put pressure on states to send people to the court or it can try suspects in absentia.

Lebanon's ambassador to the Netherlands, Zeidan Al-Saghir, said the court was a step towards the Lebanese people's belief "that they can reconstruct and rebuild what has been destroyed by war. What Lebanon is asking you is to serve justice. Justice is our request."