Libya’s foreign minister Musa Kusa defects to UK (UPDATES) (VIDEO)

BENGHAZI, Libya — Libya's foreign minister was said to have "electrifying" information on Muammar Gaddafi's role in terrorist atrocities across Europe and was being questioned in Britain on Thursday after his defection there.

Musa Kusa flew into an airport near London on a military flight late Wednesday amid claims from Tripoli that he was on a diplomatic mission.  His defection cast a shadow over Gaddafi's significant advances against outflanked rebel forces in the past 24 hours.

Despite his "electrifying" information, as reported by the Telegraph, British Foreign Secretary William Hague said Kusa would not be granted diplomatic immunity from prosecution.

Scottish prosecutors investigating the Lockerbie bombing, meanwhile, have formally requested access to Kusa, a right-hand man to Gaddafi for more than 30 years.

As Gaddafi's resurgent military forces continued to drive the rebels into retreat, U.S. officials admitted that the CIA had sent teams on covert operations into the midst of the conflict.

The revelation came amid international debate over whether the West should act to arm the poorly-equipped rebels who appear to be unable to capitalize on advantages offered by allied air strikes.

Fighting along Libya's main coastal road focused on the oil town of Brega on Thursday, where rebels were gathering after beating a hasty retreat from clashes earlier this week near Ras Lanuf and Gaddafi's ancestral home of Sirt.

Reuters said some rebels were pushing back as far east as Ajdabiya, the last major town before their stronghold of Benghazi, fleeing a sustained barrage of rocket fire from Gaddafi's forces.

In London, where Prime Minister David Cameron on Wednesday echoed U.S. Secretary of State Hillary Clinton in saying that arming the rebels would not violate a U.N. weapons embargo, there were calls for Gaddafi's allies to join Musa Kusa in defecting.

"Musa Kusa is one of the most senior members of the Gaddafi regime and has been my channel of communication to the regime in recent weeks and I have spoken to him several times on the telephone, most recently last Friday," Hague told reporters.

"His resignation shows that Gaddafi's regime, which has already seen some defections to the opposition is fragmented, under pressure and crumbling from within.

"Gaddafi must be asking himself who will be the next to abandon him. We reiterate our call for Gaddafi to go."

Hague afformed that Kusa, Gaddafi's former spy chief, would not be granted any immunity from prosecution, exposing him to possible legal action over allegations about involvement in terrorist activities.

Kusa has been accused of masterminding the 1988 bombing of a Pan Am passenger flight over the Scottish town of Lockerbie which left 270 people dead. As a former intelligence chief, he is also believed to have information over the killing of a British policewoman outside the Libyan embassy in London in 1984.

In Washington, details about the CIA's involvement in Libya were also raising questions just days after President Barack Obama gave televised assurances that U.S. troops would not be used on the ground in the North African country.

A U.S. intelligence officer, speaking on condition of anonymity, told the Associated Press that the CIA had been involved in the recovery of a F-15 Strike Eagle crewman whose aircraft crashed in Libya due to mechanical failure on March 21.

The Washington Post said covert CIA teams had been deployed to gather intelligence on the identities and capabilities of rebel forces under orders from Obama. The move appears partially motivated by fears of Al Qaeda or extremist infiltration of the opposition movement.

"Such operations are fraught with risks," the Post said. "The CIA’s history is replete with efforts that backfired against U.S. interests in unexpected ways. In perhaps the most fateful example, the CIA’s backing of Islamic fighters in Afghanistan succeeded in driving out the Soviets in the 1980s, but it also presaged the emergence of militant groups, including Al Qaeda, that the United States is now struggling to contain."

The convoy of retreating militias, unarmed volunteers and random teens fled to the next trash-strewn gas station before another barrage pushed them back again. By mid-afternoon rockets struck Brega itself and the flight continued to the gates of Ajdabiya, a city the rebels had taken with the help of allied air strikes only three days before.

Losing Ras Lanuf and Brega, each now bombed-out and abandoned cities, is a huge blow to a revolutionary force that had expected only days ago to launch an offensive on Gaddafi’s hometown of Sirt and then move on to Tripoli.

Among the rebels, there was speculation that their ranks had been infiltrated by Gaddafi's spies as they struggled to justify the ease with which loyalist forces have dominated the recent ebb and flow of fighting along the east-to-west highway.

As the rebels lost their grip on Brega on Wednesday, families were seen fleeing Ajdabiya, heading back toward Benghazi. Lines of cars, packed with clothes and young women, jammed the road out of town.

A first aid volunteer, Faraj Ali, 46, said at least two men were wounded in Ras Lanuf and two in Brega today. More casualties were avoided, she said, because Ras Lanuf is deserted. Families from Brega, who had just returned yesterday, also fled, crowding onto the chaotic highway.

At the gates of Ajdabiya, some eager young soldiers — frustrated by the lack of progress — argued about what to do next. Some wanted to rush back toward the front, despite their lack of weapons. An older man said the they should not go forward and waste their lives.

“I want to die!” one of the young men said. But he was held back.

The scene highlighted the growing tension and frustration among the rebel ranks, which are becoming more and more aware that they are going to need more than just air strikes from the international community if they are going to defeat Gaddafi and push all the way to Tripoli.

The rebel army, really, is not an army at all. It is a collection of civilian volunteers who have little to no military training. A command structure is almost non-existent.

There are hundreds of teens on the front lines armed with nothing but sneakers, cigarettes and maybe a bed roll. One carried antiquated binoculars and an empty pistol holder. A 17-year-old named Madi said he was at the front lines just to hang out.

The older and better-armed fighters were using what appeared to be an old Libyan Army base as a staging point outside Ras Lanuf on Wendesay. One group of six men in a windshield-less Toyota strapped with a 106-mm cannon, ammunition and bags, stopped to coordinate with other similarly armed trucks.

Adil Alassi, a bearded man who acted as their commander, led the first truck. Alassi’s group was a random collection of ages and occupations, among them a fisherman, a photographer and a volunteer from Egypt.

The older rebels, like Salem, 42, dressed more militarily than some of the younger ones like Akram Swaib, 21, who resembled a fashion model. He said he began his revolutionary career throwing rocks at Gaddafi police in his hometown of Beda.

These various groups operate semi-independently, pouring their own gas from a commandeered gas station.

Members of these groups seem to come and go, but there is a core that always remains. One grizzled looking soldier, Khalid El-Jani, 42, said he fired back into Ras Lanuf at 1 a.m. last night and slept in Brega.

“There’s different groups, but always the same weapon,” referring to the four-barreled anti-aircraft gun.

No rebel commander will give any estimates on the number of forces they command and they probably don’t know. Another commander, Abdul Mana El Ruweity, 42, who said he has a master’s degree in marketing, has been in charge for all of 10 days.

There also appears to be a growing number of fighters coming who call themselves mujahedeen. Truckloads of men, many of them sporting long beards, said they had come to fight in the name of God.

“I don’t want to be famous, one 21-year-old from Derna said, “I do this for God.”

“I just want to pray,” said Asad Abidi, 33. “Gaddafi said we can’t pray.”

All the rebels can pray for now is for a new round of air strikes, and maybe some new weapons, to again stop Gaddafi’s advance toward Benghazi.

— Barry Neild contributed to this report from London