MONTPELLIER, France — The cellphone's trail led from bloodstained Fallouja to the engineering school here, a modern campus where researchers in white coats stroll past labs and the breeze rustles through trees in courtyards dotted with pine cones.
Two years ago French investigators, aided by U.S. intelligence, detected calls from Iraq to a central figure in a suspected extremist cell in Montpellier. French intelligence officials say the calls came from a militant leader in Fallouja involved in the grisly killing of four American military contractors by a mob on March 31, 2004, an incident that became an icon of the savage conflict in Iraq.
The suspected cell included a group of Moroccan students accused of studying electronics, computer technology and telecommunications in the service of a North African terrorist group allied with Abu Musab Zarqawi, the leader of Al Qaeda in Iraq. The group is sending fighters to Iraq, developing alliances across North Africa and plotting attacks in Europe, investigators say.
Officials say the case of the students, several of whom are under arrest, also illustrates a wider effort by terrorist networks to use universities and the Internet to replace former training camps in Afghanistan.
The well-off suspects appeared to thrive in this cheerful Mediterranean college town: dating, cramming for exams, hitting bars and nearby beaches. But their courses allegedly were a cover for acquiring expertise and designing explosive detonators for the network.
"They oriented their scientific studies to learn terrorist techniques," a senior French anti-terrorism official said. "As people like this acquire knowledge and advance in the scientific community, they could become very hard for the police to detect. It was all quite sophisticated."
A number of top figures in Al Qaeda have academic backgrounds in the sciences. Khalid Shaikh Mohammed, the alleged mastermind of the Sept. 11 attacks, is an engineering graduate, as were Mohamed Atta and other members of the Hamburg cell that produced pilots for the attacks. Ramzi Ahmed Yousef, the convicted ringleader of the first World Trade Center bombing in 1993, is another engineer-turned-militant.
In a recent book titled "The Next Attack," two former National Security Council experts say that militants remain obsessed with developing technological capacity. The book describes bomb makers using Internet forums to reach out to academics for advice about electronics and chemistry.
The "responses suggest jihadists are able to draw on a wide range of highly skilled experts and that a significant number of Muslim scientists are prepared to help," Daniel Benjamin and Steven Simon write.
Friends of the suspects here question some of the evidence against them, including their alleged level of technical expertise. Nonetheless, the friends agree that extremist activity has grown at the University of Montpellier, where the approximately 1,100 Moroccan students are the biggest contingent of foreigners.
"There is no question there is recruitment, especially at the science faculty," said a Moroccan student leader who spoke on condition of anonymity. "I think it's because the science students are more naive. And at the same time, they are useful."
The suspect students arrived in Montpellier in 2002 to find an immigrant community that is warm, welcoming and relaxed about class distinctions. Investigators say the students befriended Moroccan laborers involved in hard-core radicalism. At soccer games, prayers and traditional meals, the group coalesced around a key figure: Hamza Safi, a 21-year-old house painter and agricultural worker.
Three of the students were Hakil Chraibi, 23, son of a French-Dutch mother and a Moroccan doctor who had also studied here; Reda Barrazouk, 24, from an upper-middle-class Casablanca family; and Youcef Bouzzag, 21, also of Casablanca, whose father works for an international oil company.
In contrast to the dour and withdrawn attitudes of most members of the Hamburg cell, the engineering students enjoyed the local nightlife and became well-known leaders in Moroccan student circles, investi gators and friends say.
Chraibi looked and sounded more French than Moroccan, and often visited maternal relatives in nearby Narbonne. He played flamenco guitar and was an emcee at a North African cultural show. He dated women from Scandinavia and Britain, his friends say.
Barrazouk enjoyed pubs, playing soccer and excursions to the French and Spanish coasts. But friends said he also seemed naive and overly deferential.
Despite their Western ways, the students were devout Muslims, praying five times a day, according to their friends. The U.S.-led invasion of Iraq in 2003 pushed them over the line, the anti-terrorism official said. They spent hours discussing Iraq in sessions dominated by Safi, who declared that the time had come for action.
"Iraq is the key," said the anti-terrorism official. "Iraq is both land of jihad and a factory for terrorists."