BENGHAZI, Libya - The head of the rebel National Transitional Council says the rebel's chief military commander had been arrested for investigation into complaints of mismanaging his forces and was killed while being transported to a safer place.

Mustafa Abdul-Jalil dismissed earlier reports that Abdel-Fattah Younis had been killed for treason. He told reporters Saturday that a committee is still investigating the circumstances of his death but the killers have been identified.

Younis' body was found dumped outside the rebels' de facto capital of Benghazi on Thursday along with the bodies of two colonels who were his top aides. They had been shot and their bodies burned.

Witnesses have said they were killed by fellow rebels after being taken into custody on suspicion of treason.