BENGHAZI – The head of the Libyan rebels’ armed forces and two of his aides were killed by gunmen Thursday, the head of the rebel leadership said.

Head of the rebel forces Abdel Fattah Younes gestures during a news conference in Benghazi in this April 5, 2011 file photo. Younes was shot dead by assailants on July 28, 2011 according to Libyan rebel leader Mustafa Abdel Jalil. Younes was killed by assailants after he had been summoned before a judicial committee that was looking into the military operations. REUTERS/Esam al-Fetori/Files

The death of Abdel Fattah Younes was announced at a press conference in the de facto rebel capital, Benghazi, by the head of the rebels’ National Transitional Council, Mustafa Abdul Jalil. He told reporters that rebel security had arrested the head of the group behind the killing.

Rebel security had arrested Younes and two of his aides early on Thursday from their operations room near the rebels’ eastern front.

Security officials said at the time that Younes was to be questioned about suspicions his family still had ties to Muammar Gaddafi’s regime.

Younes was Gaddafi’s interior minister before defecting to the rebels early in the uprising, which began in February.

Jalil said that Younes had been summoned for questioning regarding “a military matter.” He said Younes and his two aides, a colonel and a major, were shot before they arrived for questioning.Al Jazeera’s Tony Birtley, reporting from Benghazi, said that the body had not been handed over yet. “[Younes] is a man who was a target,” Birtley said. “It is a question of who was he targeted by: Pro-Gaddafi loyalists or people on the opposition side who didn’t actually like his politics because there were questions about where his loyalties truly lay.”

Jalil called Younes “one of the heroes of the 17th of February revolution,” a name marking the date of early protests against Gaddafi’s regime.

He said Gaddafi was seeking to break the unity of rebel forces but issued a stiff warning about unaffiliated “armed groups” in rebel-held cities, saying they needed to join the fight against Gaddafi or risk being arrested by security forces.