The prosecutor of the United Nations tribunal set up to bring to justice the assassins of former Lebanese prime minister Rafik Hariri filed the first indictment in the case Monday, the court announced.
But details of suspects named in the indictment and the charges against them were not released.
Hariri was killed along with 22 other people by a huge truck bomb blast on Feb. 14, 2005, on Beirut's Mediterranean sea front.
Sheik Hassan Nasrallah, leader of Shia militant group Hezbollah, said last year he expects members of his group to be charged. The Iranian- and Syrian-sponsored group fiercely denies any role in the killing.
Hariri was a Sunni, and many Lebanese worry that if the tribunal draws links between the assassination and Hezbollah it could provoke bloodshed between Lebanon's Shia and Sunni communities.
Tribunal registrar Herman van Hebel said in a statement that prosecutor Daniel Bellemare sent the indictments to Judge Daniel Fransen, who must decide whether to confirm or dismiss them or ask for more evidence.
A billionaire businessman, Hariri was credited with rebuilding Lebanon after its 15-year civil war.
Fransen is expected to take six to 10 weeks studying the evidence before reaching a decision. The names of suspects and evidence against them will only be released if he decides the evidence is strong enough to merit putting them on trial.
News of the indictment came with Lebanon's government plunged into turmoil by the resignation last week of Hezbollah and its allies from a broad coalition administration led by Hariri's son, Saad.
Hezbollah quit the government after Saad Hariri refused to renounce the UN-backed tribunal investigating his father's killing.
Nasrallah has said the group "will cut off the hand" of anyone who tries to arrest any of its members.