Four arrest warrants have been issued by the UN-backed tribunal investigating the 2005 murder of Lebanon's former Prime Minister Rafik Hariri, the court said.
Hariri's son, Saad, welcomed the indictments and described them as a "historic moment" for Lebanon.
Local reports say the warrants name senior members of the Shia militant and political group Hezbollah.
Hezbollah has repeatedly denounced the tribunal and vowed to retaliate.