For all their advances on the battlefield, concerns remain about the Libyan rebels' unity.

The death of Abdel Fattah Younes, the former commander of their armed forces, and his close aides has exposed deep divides among rebel leaders. An investigation into the murders has so far not found any suspects.

The families of the dead men say that they believe the opposition's National Transitional Council (NTC) has a hidden agenda.

Al Jazeera's Tony Birtley reports from Benghazi, eastern Libya.