Four Hezbollah members went on trial in absentia at a UN-backed tribunal on Thursday accused of murdering former Lebanese premier Rafiq Hariri in a 2005 car bombing, with sectarian tensions running high at home.
The trial opened in a suburb of The Hague nine years after the huge Beirut blast that killed the billionaire Hariri and just hours after another car bombing killed at least three in a Hezbollah stronghold near the border with war-ravaged Syria.
"We will proceed as if the accused are present in the courtroom and have pleaded not guilty," judge David Re told the Special Tribunal for Lebanon (STL).
"The onus is on the prosecutor to prove their guilt."
The STL is unique in international justice as it was set up to try the perpetrators of a terrorist attack and because it can try the suspects in absentia.
A packed public gallery looked on as the repeatedly-delayed proceedings began, with a large scale model of downtown Beirut where the 2005 attack happened on a table before judges.
Hariri's son Saad was sat in the courtroom, at the back behind the victims' representative. His hands were folded as he listened attentively.
The February 14, 2005 seafront blast killed 22 people including Damascus opponent Hariri and wounded 226, leading to the establishment by the UN Security Council of the STL in 2007.
Although the attack was initially blamed on pro-Syrian Lebanese generals, the court in 2011 issued arrest warrants against Mustafa Badreddine, 52, Salim Ayyash, 50, Hussein Oneissi, 39, and Assad Sabra, 37, all members of Syrian-backed Shiite movement Hezbollah.
A fifth suspect, Hassan Habib Merhi, 48, was indicted last year and his case may yet be joined to the current trial.
"No one in Lebanon can fail to have been affected directly, or indirectly, by the attack in downtown Beirut that on 14 February 2005, killed Mr Rafiq Hariri," said chief prosecutor Norman Farrell.
"The people of Lebanon have a right to this trial and to seek the truth," he said, showing the court a photograph taken shortly after the blast of smoke, flames and Hariri's vehicle on fire.
The four suspects have been charged with nine counts, ranging from conspiracy to commit a terrorist act to homicide and attempted homicide.
Prosecutors allege that Badreddine and Ayyash "kept Hariri under surveillance" before the Valentine's Day suicide bombing, while Oneissi and Sabra allegedly issued a false claim of responsibility to mislead investigators.
Hariri, Lebanon's Sunni prime minister until his resignation in October 2004, was on his way home for lunch when a suicide bomber detonated a van full of explosives equivalent to 2.5 tonnes of TNT as his armoured convoy passed.
A video was then delivered to the Beirut office of pan-Arab satellite broadcaster Al-Jazeera in which a man "falsely claimed to be a suicide bomber on behalf of a fictional fundamentalist group called 'Victory and Jihad in Greater Syria'," prosecutors said.
They will aim to prove the four men's involvement through tracking their alleged use of mobile phones before, during and after the attack.
Vincent Courcelle-Labrousse, Oneissi's court-appointed lawyer, told AFP ahead of the trial that "there is a huge disproportion between the prosecution and the defence's means, time and financial resources."
"We must defend the accused, who are not even here and without having had any contact with them."
The STL initially sparked fierce debate in Lebanon, sharply divided into the camp led by Hezbollah and its rivals in the March 14 movement, set up in the wake of Hariri's assassination and led by his son Saad, himself a former prime minister.
The powerful Hezbollah has denied responsibility for the attack, and its leader Hassan Nasrallah has dismissed the tribunal as a US-Israeli conspiracy, vowing that none of the suspects will be arrested.
Sectarian tensions have soared in Lebanon since Hezbollah openly intervened in the conflict in neighbouring Syria alongside President Bashar al-Assad's forces last year.
A car bombing on Thursday, likely a suicide attack, killed at least three people in downtown Hermel, a stronghold of Lebanon's Hezbollah near the border with Syria.
Syria and Hezbollah were blamed for the December 27 assassination of former finance minister Mohamed Chatah, an aide to Saad Hariri, in another downtown Beirut bombing.
Chatah was the ninth high-profile critic of the Syrian regime to be killed in Lebanon since Hariri's assassination, and his death served to remind many Lebanese that no one has been held accountable for those killings.