The enemy within? Libyan rebel says commander killed by rebel faction with Islamist ties

In an ominous update to news that the Libyan rebels' military chief was assassinated, witnesses and rebel officials have said he was killed by his own side.

Former Libyan interior minister-turned-rebel commander Abdel Fatah Younis was assassinated Thursday under murky circumstances, after being summoned from the front lines to the eastern Libyan rebel stronghold of Benghazi.

Today, as Younis was given a hero's burial in Benghazi, the Libyan rebel oil minister Ali Tarhouni said Younis was killed by rebel fighters who'd been sent to retrieve him for questioning.

According to Tarhouni, "a militia leader who was asked to fetch Younis from the frontline near the oil town of Brega had been arrested and had confessed that his subordinates had carried out the killing, Reuters reported today. "The men who fired the shots remained at large."

The acknowledgment came after a rebel special forces officer, who was with Younis yesterday, said that Younis was assassinated by a faction called the Feb. 17 Martyrs' Brigade, with Islamist ties, the Associated Press reported.

The officer, Mohammed Agoury, told the AP the Martyrs Brigade resented Younis for having previously served in Muammar Gadhafi's regime. The faction is linked to the Libyan Islamic Fighting Group, which, Agoury said, was targeted in a crackdown by the Gadhafi regime.

The Feb. 17 Martyrs Brigade "is a group made up of hundreds of civilians who took up arms to join the rebellion," the AP wrote. "Some of its leadership comes from the Libyan Islamic Fighting Group, an Islamic militant group that waged a campaign of violence against Qaddafi's regime in the 1990s."

Younis, 67, a longtime Gadhafi loyalist, defected to the rebel side early in the uprising, in a major propaganda coup for both anti-Gadhafi forces and the NATO-led military coalition which has been de facto backing the rebels' fight against Gadhafi since it launched air strikes in March.

But loyalties among the little-known rebels are in question and paranoia has run high as the stalemated conflict drags on into its fifth month.

Younis--who was mourned as a martyr today--was shot, his throat cut and his body burned, Reuters reported, citing the commander's nephew.

The United States and UK issued cautious statements on Friday, saying Younis' killing will set back rebel efforts, but shying away from attributing responsibility.

"We have not been able to confirm who is at fault," State Department spokesman Mark Toner told The Envoy Friday. "But clearly, it's a difficult situation and a challenge for the TNC [Transitional National Council], and it's important that in this period, they remain unified and focused on the ultimate goal to remove Gadhafi from power and bring about a democratic transition."

Washington announced earlier this month that it would grant interim diplomatic recognition to the Benghazi-based rebel coalition known as the Transitional National Council.

But there are also growing signs that the United States and its allies are increasingly uneasy about the Libya intervention and are seeking ways to accelerate its end.

The latest reports from Benghazi about divisions within the rebel ranks are certain to increase western allies' trepidation about the faction with whom they've effectively joined up in the ill-conceived intervention.