Tripoli, Libya (CNN) -- The killing on Thursday of the top rebel military commander shows that those forces are in disarray, a spokesman for Libyan leader Moammar Gadhafi said Friday.
Gen. Abdul Fattah Younis and two other rebels were killed after the country's main rebel organization, the Transitional National Council, sought to question him about military matters and allegations that he or those close to him had ongoing ties to Gadhafi, Younis' supporters said.
Younis' killing represents "more proof that the transitional council of the traitors is not able to lead any sort of government or have any control of eastern cities of Libya," said Musa Ibrahim, the Gadhafi spokesman.
Ibrahim accused two members of al Qaeda of having arrested Younis with the help of the Transitional National Council and subsequently charging Younis with treason for "betraying the cause."
But the abductors knew that a fair trial would have been lengthy and that Younis' tribe would have intervened to help him, so they killed him, Ibrahim said. "He was shot and his body was immediately disfigured," he added.
The killing shows that "al Qaeda is the real power among the rebels," he said, repeating Gadhafi's assertion that rebel forces are allied with al Qaeda. "They have the most soldiers; they have the training; they have the weapons; they have the faith -- a wicked faith; they have the strategies."
The killing also sends a powerful message to other tribes: "Try to exclude us from your settlement, your political settlement, and this is your fate," Ibrahim said.
Younis was killed along with a colonel and a lieutenant colonel, the Transitional National Council said in a prepared statement. No further details were immediately released.
Mohammad Ethish, a member of a rebel military council, released a statement that seemed to imply that Gadhafi loyalists had something to do with the death.
"This incident will increase the will and courage of the rebels, and it will even get us close together to reach the home of the tyrant," Ethish said. "We promise our brothers in the East that we will do the impossible to avenge the death of Abdul Fattah Younis, and we promise that we will increase our blows and empower our will. Until we capture the tyrant Moammar Gadhafi."
The deaths have provoked questions and stirred speculation that they might cause a rift among opposition leaders.
"We really don't know what happened yet," said Marina Ottaway, senior associate of the Carnegie Endowment for International Peace's Middle East program. "Politically, it's a reminder of how tenuous a coalition it is."
Rebels have been battling government troops in a fight to oust Gadhafi, who has ruled the North African nation for nearly 42 years.
NATO has used air power to enforce a U.N. resolution protecting civilians from the regime, and world powers have announced their support for Libya's rebel umbrella group.
This week, the United Kingdom joined the United States and other Western powers in recognizing the TNC as the legitimate governing authority in Libya, a decision that could steer millions of dollars to the opposition.
Younis had served as interior minister in Gadhafi's government until February, when he defected to the Benghazi-based rebel movement.
A onetime general in Gadhafi's army, Younis told CNN in February that he switched sides after Gadhafi told him he planned to bomb Benghazi -- a move Younis said would have killed thousands.
A young man in a tan uniform who spoke in Benghazi after Friday Muslim prayers said on rebel TV that Younis "was assassinated by him like the other martyrs of Libya" and called for "revenge for everyone who took part in this crime." It wasn't clear whom he was implicating in Younis' death.
The man said that "knowing the truth of what happened to him and avenging his death is a debt every Libyan man and woman owes. My message to Mustafa Abdel Jalil is we will be with you on this path," the man said, referring to the leader of the rebels' government.
Alistair Burt, the British Foreign Office's minister for the Middle East and North Africa, said, "Exactly what happened remains unclear." He added that the "killing will be thoroughly investigated."
"We agreed that it is important that those responsible are held to account through proper judicial processes."
Sir Richard Dalton, a former British ambassador to Libya and associate fellow for the Middle East and North Africa Programme of the London-based Chatham House, said "one scenario is revenge by Tripoli."
However, Dalton said, the ultimate impact of the killing on the opposition movement will depend on the facts that emerge about the killing.
"They've been promising it for a while," he said of the Gadhafi government. "Right from the start, they've threatened people who've turned away. There are stories that AFY (Younis) had rebuffed approaches by Tripoli."
There have been tensions between different parts of the opposition forces, Dalton said. So a "second hypothesis" is that a quarrel got "out of hand. But he warned not to jump to conclusions about the significance of a "single episode."
"We haven't got much to go on," he said. "I think our governments will find out soon."
Ottaway, the Carnegie Endowment scholar, said the killing raises questions about the rebel council.
"It's clear there are divisions" within the Transitional National Council, she said. "There are suspicions of some of the people who went from being close allies (of Gadhafi), as Younis was, to joining" the rebels.
The motives of those who switched sides have been questioned by people who weren't sure whether they had truly made the transition or were just pretending to have changed. There has been speculation, she said, that Younis might have been dealing somehow with Gadhafi.
"The main point perhaps is that the unity at the Transitional National Council is tenuous at best. This is a strange coalition at best," she said. "They are very aware of the fact that they are not an organization that represents the entire country."
As for how the killing might affect the rebels' military effort, Ottaway said it's not clear how much control Younis had. She pointed out that the killing occurred on the same day rebels embarked on an offensive in western Libya. The fighters said their forces captured five towns and surrounded a sixth in the plains below the Nafusa mountain range, which borders Tunisia.
Mark Quarterman, a senior adviser and director of the Center for Strategic and InternationalStudies' Program on Crisis, Conflict and Cooperation, said the "potential implications" of the death are "very worrisome" and could help the Gadhafi regime in the short run.
The death has had the effect of "roiling rebel politics," Quarterman said. The killing has fomented anger among members of Younis' Obeidi tribe, according to news reports.
Quarterman, an expert on the Libyan crisis, said the killing undermines the bet NATO powers have made that, by enforcing the U.N. resolution protecting Libyans, they would give rebels space to defeat Gadhafi forces.
Quarterman noted that Younis had been engaged in a dispute with another rebel commander, Khalifa Hifter.
"They seem unable to take and hold territory. This makes things worse," Quarterman said. "You can't have a lot of faith and confidence in forces saying, 'I'm the commander, no I'm the commander.'
"If this disarray does continue, this only benefits Gadhafi. And it makes the coming of a post-Gadhafi Libya that much more distant."
There has been talk among world powers about negotiated settlements and scenarios that could include Gadhafi remaining in Libya after the conflict ends, Quarterman said.
The international sense that the conflict would end quickly with "capitulation on the part of the Gadhafi regime is fading," Quarterman said.
"As a result, the end game is seeming much more murky."
Ivan Watson reported from Tripoli and Joe Sterling reported from Atlanta.