TRIPOLI, Libya (AP) — A Libyan military tribunal investigating the death of a former military chief has quit.

This came after the tribunal's decision to summon the former head of the transitional government prompted a Tripoli militia to block roads in protest, the latest sign of instability in Libya.

Abdel-Fattah Younis served as ousted leader Moammar Gadhafi's interior minister until last year's revolution. He was killed in July 2011 in custody after he was arrested on suspicion of treason.

Tripoli militia forces blocked roads for a third day to protest the court's summoning of Mustafa Abdul-Jalil, former head of National Transitional Council.

In a statement Wednesday, the tribunal declared, "No one is above law," and hoped for "retribution for killers of the martyr" Younis.

The tribunal sent the case back to the military prosecution.