The trial of four men alleged of murdering former Lebanese Prime Minister Rafik Hariri begun at The Hague on Thursday.
The suspects have not been arrested and are being tried in absentia.
The accused are alleged associates of the Syria-backed militant movement Hezbollah which has denied any involvement in the assassination of the Lebanese premier.
Hariri and 22 others were killed by a massive car bomb in Beirut in 2005.The killings polarised Lebanon and led to the withdrawal of Syrian troops.
The UN Security Council of the Special Tribunal for Lebanon was also established following the event, in 2007.
In his address at the start of the trial, judge David Re said it had been decided that all necessary steps had been taken to try to bring the accused to court.
Prosecutor Norman Farrell in his opening statement stated that the amount of explosives used showed the attackers had intended to send “a terrifying message and to cause panic among the population of Beirut and Lebanon”.
Hariri’s family members were also present at the trial.