The indictments will almost certainly target Hezbollah, the powerful Shiite movement backed by Syria and Iran.
Four of its members, including two senior figures, were indicted in July 2011 for the assassination that killed Hariri, the leader of Lebanon's Sunni Muslims, and forced Syria to withdraw its military forces from its tiny neighbor.
Hariri, a billionaire tycoon who was five times Lebanon's prime minister, was killed Feb. 14, 2005, in a massive truck bombing that wiped out his six-car motorcade and killed 22 other people.
It was the most critical political assassination in Lebanon, where the murder of political leaders has been commonplace since the 15-year civil war broke out in April 1975.
Hariri was slain after he declared his opposition to Syria's control of Lebanon that began in 1976 and sought to end the quasi-occupation by some 30,000 Syrian troops and a vast army of intelligence operatives.
His assassination deepened Lebanon's smoldering sectarian divisions, with a Sunni-Christian alliance demanding the return of full Lebanese sovereignty, and a rival Shiite-Christian coalition, dominated by Hezbollah, supporting the Damascus regime.
On Monday, the tribunal ruled from its headquarters in the Netherlands that it has the jurisdiction to put Hariri's alleged killers on trial in absentia.
Defense lawyers representing the four Hezbollah suspects had claimed in pretrial motions the tribunal violated Lebanese sovereignty and couldn't guarantee a fair trial to those indicted. They claimed it was biased in favor of the Western- and Saudi-backed, Sunni-led March 14 political coalition headed by Hariri's son, Saad.
The tribunal, the first international tribunal to deal with terrorism as a distinct crime, was set up following a long U.N. investigation that linked Hezbollah personnel -- although not the organization itself -- to the assassination of Hariri.
The Syrian regime and its intelligence apparatus, a key pillar of the dictatorship, were initially seen as the prime suspect but in the end, analysis of mobile telephone traffic led investigators to indict the Hezbollah personnel.
In the minds of many Hariri supporters, the Syrian regime of President Bashar Assad is still held responsible, largely on the premise that Hezbollah wouldn't have assassinated someone of Hariri's international status without the green light from Damascus.
Meantime, Hezbollah, which dominates the current government that ousted a Saad Hariri coalition in January 2011, has sought to systematically discredit the tribunal as a U.S.-Israeli conspiracy.
Hezbollah Secretary-General Hassan Nasrallah refuses to hand over the suspects and threatens to "cut off the hands" of anyone who tries.
The government insists it can't locate the men.
The tribunal hasn't identified the suspects it expects to indict. But it's not clear -- and even seven years after Hariri was killed, there's an awful lot about this affair that remains murky -- why these individuals were not indicted earlier.
Some people believed to have been involved in the Hariri plot have disappeared. Others have died, some in suspicious circumstances.
On Oct. 12, 2005, the Syrian regime said Gen. Ghazi Kenaan, the head of Syrian Military Intelligence in Lebanon in 1982-2002 who had intimate dealings with Hariri, shot himself in his Damascus office after denying a financial links to Hariri.
To this day, it's widely believed Kenaan was silenced by the regime after he'd been questioned by U.N. investigators. Damascus denies that.
But initial reports to the Security Council by the chief investigator at the time, German Judge Detlev Mehlis, said Kenaan was one of several Syrian and pro-Syrian Lebanese security chiefs who plotted the assassination.
The council excised Kenaan's name from the public version of the report.
On Feb.12, 2008, Hezbollah's iconic and elusive military chief, Imad Mughniyeh, who many saw as the brains behind the Hariri killing, was assassinated in Damascus by persons unknown.
On July 19, two weeks ago, Assef Shawkat, former head of Syrian Military Intelligence and Assad's brother-in-law, was killed, with other senior regime figures, in a bombing inside one of the most secure buildings in Damascus.
Shawkat, a dominating figure in Assad's inner circle, was widely suspected to have been involved in planning the Hariri hit.