When news outlets reported this morning on the death of Libyan rebel commander Abdel Fattah Younes, they generally focused on the mystery that had surrounding the incident since rumors of his demise began swirling yesterday, and especially after rebel leader Mustapha Abdul Jalil didn't identify the "gunmen" or have possession of the military chief's body when he announced Younes' death. Had Muammar Qaddafi's forces killed Younes, a former interior minister, for defecting to the opposition in February? Or had the rebels carried out the assassination because they suspected Younes of collaborating with Qaddafi? Could military rival Khalifa Hifter have orchestrated the attack as part of an internal power struggle?

While theories are still being floated this afternoon (the Qaddafi regime is pointing a finger at al-Qaeda), there's also mounting evidence that the rebels themselves killed Younes. Rebel minister Ali Tarhouni tells Reuters that rebel fighters who were dispatched to the eastern front to bring Younes back to Benghazi for questioning killed him and and dumped his body outside Benghazi. The AP, citing two Libyan officers, reports that fighters from a rebel faction known as the February 17 Martyr's Brigade killed Younes after opposition leaders arrested him "on suspicion of treason." One unnamed officer says the assassination was "an act of vengeance by rebels" rather than an order from rebel leaders, and that two rebel fighters shot Younes as he left the Defense Ministry after a round of questioning over a letter linking him to Qaddafi. "The men's leader was shouting 'Don't do it!' but they shot Younes and his two aides, and took their bodies in their car and drove away," the officer recounted.

If the most recent reports are accurate, it would signal serious divisions within the Libyan opposition that could cripple the rebels in their fight against Qaddafi. The AP explains that some of the leaders of the February 17 Martyr's Brigade are members of an Islamist militant group that Younes and Qaddafi battled in the 1990s, and may therefore have been seeking revenge. Noting that Younes's tribe--the Obeidi--greeted news of his death with "gunfire and angry threats," The New York Times suggests an impending tribal feud could drive a wedge through the rebel cause and thwart the NATO-led military intervention:

The specter of a violent tribal conflict within the rebel ranks touches on a central fear of the Western nations backing the Libyan insurrection: that the rebels' democratic goals could give way to a tribal civil war over Libya's oil resources. Colonel Qaddafi has often warned of such a possibility as he has fought to keep power, while the rebel leaders have argued that their cause transcends Libya's age-old tribal divisions.

On Friday, thousands marched in Younis' funeral procession in Benghazi: