Col. Moammar Kadafi has depicted this coastal city of squat concrete homes and graceful blue harbor as the staging ground for an Al Qaeda takeover of Libya.
A radical Islamic caliphate, Kadafi claims, is based in Derna, inside rebel-held eastern Libya, and is directing the uprising against him.
That characterization draws a belly laugh from Mabrouk Salama, an Irish-educated chemistry professor who serves on the rebel leadership council in Derna.
"Al Qaeda? Here? Ha!" Salama said, shaking his head. "It's just Kadafi's way of trying to scare America."
At the same time, a schoolteacher, Abdelhakim Hasadi, who has been described by Kadafi as the leader of a radical Islamic emirate in Derna, has been allowed to run his own militia of about 150 gunmen who control security and checkpoints in the town. Among them are a half-dozen who fought in Iraq, including two who had contact with Al Qaeda, according to a close friend and follower of Hasadi.
As the U.S. debates arming or training the outgunned rebels battling Kadafi's forces, some U.S. political and military leaders have expressed alarm over the possibility of Islamic extremists' influence on the rebel leadership.
The focus has been on the rebels' de facto capital of Benghazi and on Derna, 170 miles to the east. Derna caught the attention of U.S. intelligence in 2007, when documents captured by U.S. forces in Iraq revealed more extremists came to Iraq from Libya in 2006 and '07 than from any other country except Saudi Arabia, with most of them hailing from Derna.
A 2008 cable from the U.S. Embassy in Tripoli, made public by WikiLeaks, described Derna as a "wellspring for Libyan foreign fighters" serving the group Al Qaeda in Iraq.
It is impossible for an outsider to discern the motives, intrigues or heartfelt beliefs of Libyans in cities like Derna, which was sealed off from the outside world for four decades under Kadafi. But appearances, at least, do not suggest a deep Al Qaeda presence here.
Zahi Mogherbi, a retired political science professor in Benghazi who wrote a research paper on radical Islamic influences in Libya, said 63 men from Derna and 23 from Benghazi were among 120 Libyans who went to Iraq in 2006 and '07. Calling those numbers "fairly insignificant" in a nation of 6.5 million, Mogherbi said radical Islam had not taken root in Derna or anywhere else in eastern Libya.
"I have not seen any doctrinal movement to espouse any radical brand of Islam," he said, describing Derna as moderate and progressive by Arab standards.
"It would not be tolerated," Mogherbi said. "The people are rebelling against a dictatorship. They will not substitute this dictatorship for a radical Islamic dictatorship."
Leaders of the 15-member opposition council here say that only about half the local men who went to Iraq even survived the war, and that the rest now support the rebellion against Kadafi. Few actually had contact with Al Qaeda or returned bent on radicalizing Libya, they say.
"They're the same as us: revolutionaries who want to get rid of Kadafi and bring democracy and freedom to Libya," said Moftah Mahkrez, a member of the Derna opposition council. "This is Libya, not Afghanistan."
Anis Mahkrez, the friend and follower of Hasadi, said Al Qaeda's philosophy was alien to Libya and had little appeal here. He said Hasadi had joined the fight to depose Kadafi and that he reported to the rebel council.
However, council members acknowledge that Hasadi was allowed to keep his militia intact after it drove Kadafi's forces from the neighboring town of Qubbah during fighting in February. Anis Mahkrez, who serves in the militia, said the gunmen provide security in the absence of police.
The arrangement is unusual. In most other eastern cities, gunmen operate from individual gun trucks or private cars, not in organized militias. Security is provided by volunteers overseen by rebel-led councils.
In those cities, rebels at checkpoints typically wave Western reporters through with barely a glance. But in Derna, Times journalists entering and leaving the city were questioned and their car trunk was searched by members of Hasadi's militia.
Salama, the chemistry professor, said Mahkrez militia would soon be relieved of security duties as other rebels are trained in basic police operations. He described Hasadi as a marginal figure who gained notoriety only because Kadafi singled him out as an alleged Al Qaeda recruiter.
In fact, Anis Mahkrez said, it was Kadafi who released Hasadi from prison.
Council members said Hasadi had promised to give up his weapons and disband his militia once Kadafi was deposed. "He's not Al Qaeda. And besides, we control him," Moftah Mahkrez said.
Anis Mahkrez, who is Moftah Mahkrez's brother, described Hasadi as "a quiet schoolteacher." He added, "The only one talking about Al Qaeda in Derna is Kadafi."
When a Times reporter asked to interview Hasadi, council members said he was out of town. Hasadi recently told the Agence France-Presse news agency that he fought against foreign troops in Afghanistan and considered Osama bin Laden a "good Muslim." But he denied any ties to Al Qaeda.
Derna has past associations with at least one radical group. Extremists from the Al Qaeda-aligned Libyan Islamic Fighting Group battled the Kadafi regime in Derna and Benghazi in the mid-1990s.
Like Benghazi, Tobruk and other eastern cities, Derna is festooned with the rebels' red, black and green pre-Kadafi flag. Walls and buildings are streaked with graffiti mocking the dictator and calling for a democratic Libya. Posters of Omar Mukhtar, the Libyan nationalist hero executed by Italian colonialists in 1931 and a symbol of the rebellion, dominate the cityscape.
Rebel leaders here hardly look or sound like Al Qaeda operatives.
Salama, who was jailed under Kadafi and said he holds a doctorate from the University of Dublin, was dressed in a pinstriped business suit. Except for a neatly clipped mustache, he was clean-shaven.
Moftah Mahkrez, 44, a businessman, wore a blue blazer and designer jeans. Brother Anis, 48, who was jailed for five years by the Kadafi regime, wore a stylish black tracksuit.
Anis was once a well-known soccer player. Photos of the brothers in soccer uniforms adorn the home they share in downtown Derna.
Anis nodded vigorously when his brother said he and fellow council members controlled the Hasadi militia that includes Anis.
"My brother is loyal to football, not Al Qaeda," Moftah said.
Moftah described extremists who went to Iraq as poorly educated young men weary of living in Kadafi's police state. "Now they need pencils and paper, not Kalashnikovs" rifles, he said.
Mogherbi, the Benghazi professor who advises the rebel national council, said radical Islam provided a natural outlet for young men living under Kadafi's dictatorship.
"Their radicalization was a reflection of their antagonism toward the Kadafi regime and his neglect of the east," Mogherbi said. "Now that Kadafi no longer controls the east, there is no appeal in this radical form of Islam."
In Senate testimony last week, Navy Adm. James Stavridis, commander of NATO forces, described "flickers in the intelligence of potential Al Qaeda, Hezbollah" influence in Libya. But he said there was no evidence of "significant Al Qaeda presence or any other terrorist presence."
In Benghazi, the rebels' political leadership is dominated by Western-educated lawyers, doctors, businessmen and academics, along with several former Kadafi ministers or diplomats.
Mustafa Gheriani, a rebel spokesman who earned a master's degree from Western Michigan University, says Al Qaeda will try to take advantage of the chaos in Libya. Western-led airstrikes and missile attacks against Kadafi's forces are a bulwark against extremist overtures to young Libyan men, he said recently.
But that could change if U.S. and Western support fades, Gheriani warned. Rebel fighters might be persuaded that radical Islam is the best way to overthrow Kadafi, he said.
"They would align with the devil to get rid of this guy," Gheriani said.