Head of the rebel forces Abdel Fattah Younes gestures during a news conference in Benghazi in this April 5, 2011 file photo. [Photo/Agencies]

BENGHAZI - Libyan opposition leader Moustafa Abdel-Jalil said Thursday that the rebel forces' chief of staff Abdel Fattah Younes was killed.

The National Transitional Council (NTC) chairman Jalil told a press conference that supporters of Muammar Gaddafi were responsible for the death of Younes. Two other military leaders were also killed.

The NTC would hold a three-day mourning for the death of Younes, Jalil said in the reble's stronghold Benghazi.

The Libyan government in Tripoli has not commented on the statement of the NTC.