Four Hezbollah suspects have gone on trial accused of plotting the truck bomb assassination nine years ago of former Lebanese Prime Minister Rafik Hariri and 22 others.
The trial in The Hague opened against a backdrop of ongoing sectarian violence in Lebanon, where a car bomb exploded early today close to the country's border with Syria, killing at least three people and wounding more than 20.
Mr Hariri's son, Saad - like his late father, also a former prime minister - was in The Hague to attend proceedings along with family members of other victims of the February 14, 2005, blast.
But the suspects themselves were absent as they have not been arrested. Shiite group Hezbollah denies involvement in the murder and the group's leader, Sheik Hassan Nasrallah, has denounced the court as a conspiracy by his arch enemies - the US and Israel.
Presiding Judge David Re says prosecutors will call hundreds of witnesses in a trial likely to take months.
Beginning an opening statement expected to last into tomorrow, Prosecutor Norman Farrell told the UN-backed tribunal "the people of Lebanon have the right to have this trial, hear the evidence and seek the truth."
He said the prosecution case is made up of evidence including large amounts of data from mobile phones allegedly used by the plotters to plan and execute the bombing.
Mr Farrell showed the court photos of the aftermath of the attack, including a smouldering, rubble-strewn crater around 12 metres (40 ft) across and the flaming wreckage of the truck. He told judges attackers packed "an extraordinary quantity of high grade explosives" into a Mitsubishi truck to kill Mr Hariri.
The four Hezbollah suspects include Mustafa Badreddine, believed to have been the group's deputy military commander, who also is the suspected bomb maker in the 1983 blast at the US Marines barracks in Beirut that killed 241 Americans.
The other suspects are Salim Ayyash, also known as Abu Salim; Assad Sabra and Hassan Oneissi, who changed his name to Hassan Issa. The fifth to be indicted was Hassan Habib Merhi, who was indicted later than the other four suspects and is not officially a suspect in the trial that started today.
They are charged with terrorism and intentional homicide.
There are fears in Lebanon that the tribunal will open a new chapter of sectarian violence in a country where the Syrian civil war has spilled over with increasing frequency in the past few months. Sunni-Shiite tensions are soaring, and there has been a new wave of killings among Lebanon's Shiite and Sunni political factions.
Mr Hariri, who also held Saudi citizenship, was one of Lebanon's most influential Sunni leaders, with wide connections in the Arab world and international community. Hezbollah, a Shiite group, is backed by Shiite Iran.
In the immediate aftermath of the assassination, suspicion fell on Syria, since Mr Hariri had been seeking to weaken its domination of Lebanon. Syria has denied any role in the murder, but the killing galvanized opposition to Damascus and led to huge street demonstrations, dubbed the "Cedar Revolution," that helped put an end to Syria's 29-year military presence in its smaller neighbour.
Lebanon has a history of political assassinations for which no one has ever been held accountable. In the emotional days following his death, Hariri supporters called for an international investigation, and a UN-backed court was established in 2009.