THE HAGUE (AFP) — The tribunal created to try the suspected killers of former Lebanese premier Rafik Hariri was set to open its doors in The Hague on Sunday with no indication of a first trial date.

The Special Tribunal for Lebanon was to be officially inaugurated in a special ceremony at its new seat, the former Dutch intelligence headquarters in the suburb of Leidschendam.

The ceremony was to presided over by the tribunal’s British registrar, Robin Vincent, and addressed by Canadian prosecutor Daniel Bellemare who has hitherto led the international investigation of Hariri’s assassination in a car bombing in February 2005 that also killed 22 other people.

VIP guests at the event included UN under-secretary general for legal affairs Patricia O’Brien and Lebanese ambassador to the Netherlands Zeidan Al-Saghir.

Security around the building was tight as dozens of journalists from around the world gathered hours before the opening in the former spies’ gymnasium that will eventually house the courtroom.

In a statement marking the opening, UN Secretary-General Ban Ki-Moon called on UN member states to support and cooperate with the tribunal.

“The commencement of the tribunal’s work marks a decisive milestone in the tireless efforts by all Lebanese and the international community to uncover the truth, bring those responsible for this assassination and related crimes to justice and end impunity,” he said through a spokesperson in Washington.

The tribunal, created by a 2007 UN Security Council resolution, will apply the Lebanese penal code. It has an initial, renewable, three-year mandate.

The identities of its 11 judges, four of them Lebanese, are still being kept under wraps for security reasons.

In its early stages, the UN probe into the murder implicated top officials close to Syrian President Bashar al-Assad. Damascus has consistently denied any involvement.

In an open letter to the Lebanese people, Bellemare vowed Saturday to “do everything that is humanly and legally possible to ensure that the truth emerges and that those responsible for the crimes that fall within our jurisdiction are eventually brought to justice.”

Four Lebanese generals are in detention in Lebanon over the killing. Three others, civilians suspected of withholding information and misleading the ongoing probe, were freed on bail by Lebanon on Wednesday.

From taking office officially on Sunday, the prosecutor’s office will have 60 days to apply to the Lebanese authorities for the transfer of suspects and evidence files.

The tribunal, which has a 51.4-million-dollar budget (40 million euros) for 2009, has a separate wing of holding cells at the Dutch penitentiary in Scheveningen, which “is operational, staffed and ready to receive anyone we get,” according to Vincent.

Work on converting the spies’ gymnasium into a courtroom is unlikely to be completed before November this year.