The alleged mastermind of the truck bomb slaying of former Lebanese Prime Minister Rafik Hariri is challenging the legality of the UN-backed tribunal that indicted him and three other Hezbollah members.

The Special Tribunal for Lebanon says defense lawyers for Mustafa Badreddine filed the legal challenge on Thursday.

They claim that the Security Council abused its powers when it adopted a resolution creating the court in 2007.

Badreddine is a Hezbollah commander and the suspected bomb maker who blew up the U.S. Marine barracks in Beirut in 1983, killing 241 Americans.

He has not been arrested and the tribunal based in the Netherlands is planning a trial in absentia for him and three other suspects in the Feb. 14, 2005, bombing that killed Hariri and 22 others, including the bomber.

Hariri was one of Lebanon's most powerful Sunni leaders while Hezbollah is a Shiite group.