BEIRUT, Lebanon (CNN) -- The United Nations Sunday launched a special tribunal to prosecute the assassins of former Lebanese Prime Minister Rafik Hariri.
A statue of slain former Lebanese prime minister Rafiq Hariri stands in Beirut.
The tribunal convened at The Hague more than four years after Hariri was killed in a massive car bombing in Beirut on February 14, 2005.
The bomb, detonated as Hariri's armored motorcade passed through Beirut's fashionable seaside Corniche district, contained hundreds of pounds of explosives. It left buildings shattered and streets littered with the mangled wreckage of vehicles. The blast also killed 22 other people.
The Lebanese army was out in force on the streets of Beirut Sunday as people turned out to pay their respects to Hariri, who is buried downtown in the Lebanese capital.
The U.N. tribunal will have 11 judges, whose identities are being kept secret for their safety. Four will be Lebanese. The prosecution could take as long as 10 years, sources close to the tribunal said.
Four senior Lebanese generals are being held over the bombing, which also killed 22 other people. But many Lebanese -- as well as the United States and U.N. investigators -- believe Syria ordered the assassination. Syria denies it.
The tribunal's prosecutor, Daniel Bellemare, refused to commit when asked at a news conference Sunday if Syrians would be charged. He said the public would have to wait and see.
The U.S. State Department pledged its continued support of Lebanese judicial authorities and the tribunal's operations. The United States has promised to contribute $14 million; a request for an additional $6 million is pending approval from Congress.
In a statement issued Sunday, acting State Department spokesman Robert A. Wood said Hariri's death "was an unsuccessful attempt to undermine Lebanon's sovereignty."
He added: "The Lebanese people answered his assassination with the Cedar Revolution, leading to the withdrawal of Syrian troops and the most democratic Lebanese elections in decades."
At the time of Hariri's death, neighboring Syria had immense political influence in the country, and had maintained troops in its smaller neighbor since the 1980s, after the fighting between Israel and the PLO in Lebanon.
Hariri was admired for spearheading the rebuilding of Beirut after the country's civil war, from 1975 to 1990, and many Lebanese blamed Syria for the killing, citing Hariri's patriotism and strong sense of Lebanese independence.
The killing sparked widespread protests that led to the eventual withdrawal of Syrian troops from Lebanon and the election of an anti-Syrian bloc in parliament.
The anti-Syrian movement is known as the March 14 Alliance, named after the day millions of supporters of Hariri took to the streets, and its actions have been dubbed the Cedar Revolution, for the nation's iconic cedar trees.
Huge counter-protests also were staged by Lebanese supporters of Syria.
Along the way, U.N. investigators tasked to probe the attack found links between Syria's government and Hariri's assassination.
The Lebanese hope the tribunal will settle the case, but there are also fears it could further divide the nation and open up older wounds in the country.
The special tribunal takes over from the Beirut-based International Independent Investigation Commission, which looked into 20 other attacks and found elements linking some of them to a criminal network behind the Hariri killing, the United Nations said.
The trial will take place in a converted gymnasium in a suburb of The Hague. The U.N. says the case is expected to be ready for trial by 2010.
--CNN's Cal Perry contributed to this report.