* Cool-headed officer says key tribes still back Gaddafi
* Gaddafi building up forces in Zawiyah, west of Tripoli
By Michael Georgy
SHALGHOUDA, Libya, Aug 12 (Reuters) - About 70 percent of Libyans in Muammar Gaddafi’s main stronghold Tripoli still support him and he is in no danger of falling anytime soon, a captured Libyan intelligence officer said on Friday.
“For the most part Tripoli is stable. There is some opposition to Gaddafi but I would say he is safe,” said Brigadier-General Al-Hadi al-Ujaili, who described himself as a member of Libya’s all-pervasive intelligence service.
“Gaddafi still has the support of key tribes. He is still very strong,” said the 54-year-old father of six, who was captured wearing a tan leisure suit by rebels pushing north towards the town of Zawiyah, 50 km (30 miles) west of Tripoli.
Gaddafi is clinging to power despite a near five-month-old NATO air campaign, tightening economic sanctions and a lengthening war with rebels trying to end his 41-year rule.
The rebels have seized large swathes of the North African state, but are deeply divided and lack experience.
Reuters was allowed to speak to Ujaili, who was transported in the back of a pick-up truck, inside a concrete hut in the village of Shalghouda shortly after he was arrested.
Sitting cross-legged on a mat beside tin foil containers of old couscous, he was composed and almost defiant.
Angry rebels frequently interrupted the interview with condemnations of Gaddafi, who has ruled the North African oil-producing country for more than 40 years.
“There is opposition to Gaddafi in some parts of Tripoli like Tajoura and Souk al-Jumma,” said Ujaili. “I have heard that there are still demonstrations there. It’s a problem.”
The government is dealing it, he said. “When people get out of line they are arrested. That’s the way it works.”
Asked by a rebel “how can you do this to your own people”, Ujaili smiled and said “I will tell you the truth. There are no problems in Libya.”
He said he was arrested while driving from Tripoli to the town of Nasr, which rebels say they have taken. “I am just an administrative officer,” said Ujaili, closely studying each rebel fighter who walked into the hut.
But one rebel fighter barked back: “Tell the truth” and displayed a document signed by Ujaili authorising arrests.
Ujaili said he had been sent to Nasr to help oversee the government operation against the rebel advance towards Zawiyah, the scene of two failed uprisings against Gaddafi in the past six months of revolt.
Many of the rebels in the drive north to Zawiyah are from the town. Ujaili predicted a tough fight, even though he said Gaddafi’s forces do not have heavy weapons there.
“Gaddafi has more than 1,000 men there. They are mostly conscripts. Since the rebels have been moving he has been building up his people there,” he said.
A rebel said: “Don’t lie. You know there are African mercenaries there.”
Gaddafi denies using mercenaries. His opponents hope NATO airstrikes, advances by rebel units, defections and international isolation will prove to be too much for him.
But Ujaili said there were no signs that the supreme leader was in imminent danger of losing his 41-year grip on power.
“He is under threat, but pushing him out will be very difficult. The tribes are key. He has their support,” said Ujaili, as rebels barged in from time to time to glare at him with hatred, shaking their heads.
Ujaili seemed relaxed. At one point he was offered apple juice. But a few minutes later he began to sweat when a rebel accused him of calling the fighters “rats”, the term Gaddafi uses to describe them.
“I swear I didn’t say that. I swear I didn‘t,” he said. (Editing by Douglas Hamilton and Gareth Jones)