WASHINGTON (Reuters) - In the months before the deadly attack in Benghazi, Libya, U.S. and allied intelligence agencies warned the White House and State Department repeatedly that the region was becoming an increasingly dangerous vortex for jihadist groups loosely linked or sympathetic to al Qaeda, according to U.S. officials.
Despite those warning s , and bold public displays by Islamist militants around Benghazi, embassies in the region were advised to project a sense of calm and normalcy in the run-up to the anniversary of the September 11 attacks in the United States.
So brazen was the Islamist presence in the Benghazi area that militants convened what they billed as the "First Annual Conference of Supporters of Shariah (Islamic law)" in the city in early June, promoting the event on Islamist websites.
Pictures from the conference posted on various Internet forums featured convoys flying al Qaeda banners, said Josh Lefkowitz of Flashpoint-Intel.com, a firm that monitors militant websites. Video clips showed vehicles with mounted artillery pieces, he added.
A research report prepared for a Pentagon counter-terrorism unit in August said the Benghazi conference brought together representatives of at least 15 Islamist militias. Among the paper's conclusions: these groups "probably make up the bulk of al Qaeda's network in Libya."
Drawing on multiple public sources, the Library of Congress researchers who drafted the paper also concluded that al Qaeda had used the "lack of security" in Libya to establish training camps there. It also reported that "hundreds of Islamic militants are in and around Derna," where special camps provided recruits with "weapons and physical training."
President Barack Obama's administration has repeatedly said it had no specific advance warning of an attack like the one that killed Ambassador Chris Stevens and three other Americans in Benghazi on the night of September 11.
But the reports of militants' growing clout in eastern Libya, and attempts by violent jihadists to take advantage of fragile new governments across northern Africa fo llowing the Arab Spring, a ppear to raise new questions about whether U.S. embassies took proper security precautions, and if not, why not.
Washington has not definitively placed responsibility for the Benghazi attack on specific individuals or groups among the jihadist factions believed to be operating in or near Libya.
But U.S. officials have said that within hours of the Benghazi attacks, information from communications intercepts and U.S. informants indicated members of at least two groups may have been involved.
One is an al Qaeda offshoot, al Qaeda in the Islamic Maghreb or AQIM, which was founded in Algeria and has region-wide ambitions. The other is a local militant faction called Ansar al-Sharia, which apparently has arms both in Benghazi and in Derna, long a hotbed of radicalism.
Like other militants seeking to take advantage of democratic openings and fragile governments created in last year's Arab Spring, the two groups are apparently seeking to exploit instability in Libya after the fall of dictator Muammar Gaddafi.
The links between these groups, other jihadist organizations and the original core al Qaeda militant group founded by the late Osama bin Laden are murky at best, U.S. officials and private analysts say.
"There is a complex mosaic of extremist groups in North Africa," a U.S. counterterrorism official said. "Given AQIM's interest in expanding its reach, it's not surprising that the group is trying to gain a foothold in Libya."
While hardly sweeping the continent, violent extremist groups appear to have found ungoverned safe havens across north Africa, from Mali in the west to Egypt's Sinai in the east.
In the last month, U.S. embassies in Egypt, Tunisia and Yemen have also witnessed violent attacks.
Questions have been raised about security precautions at diplomatic facilities in those countries as well.
Tunisia, the cradle of the Arab Spring, was the scene of some of the worst recent anti-American violence. Hardline Islamists there have been accused of inciting the storming of the U.S. Embassy in Tunis a few days after the Benghazi attacks. Four protesters were killed, cars were burned and the U.S. flag was torn down and replaced with a black Jihadist banner.
"The recent violence at the U.S. Embassy in Tunis highlights the unfortunate fact that extremists are increasingly active in Tunisia," the U.S. counterterrorism official said. "It's not prime AQIM territory, but there are veteran hard-line extremists in the country with nefarious intentions."
The U.S. Embassy in Yemen - home of al Qaeda in the Arabian Peninsula or AQAP, one of the group's most dangerous offshoots - was also hard hit, and Washington sent Marines to bolster security there.
Nevertheless, last week in Sanaa, attackers shot and killed a senior Yemeni member of the embassy's security force on his way to work. Yemeni officials said the attack bore the hallmarks of AQAP.
Obama moved after the eruption of violence last month to beef up protection of U.S. diplomatic installations in the Arab world, sending in Marine contingents to several embassies and temporarily reducing the number of U.S. personnel at some posts.
The president also vowed to bring to justice those responsible for the Benghazi attack.
But the administration may have a hard time deciding whom to target. The increasingly diffuse nature of al Qaeda, its allies and sympathizers complicates the job of identifying precisely which individuals and groups were behind the attacks.
Despite signs of growing militancy in Libya, and a string of attacks on international facilities in Benghazi over the spring and summer, two compounds housing U.S. personnel remained open in the city.
State Department messages and testimony at a recent congressional hearing showed the State Department responded slowly, if at all, to requests for beefed-up security in Libya, and sometimes turned such requests down.
Just hours before he died, a State Department cable showed, Stevens met with members of the Benghazi local council, who insisted security in the city was "improving" and the U.S. government should "pressure" American companies to invest.
Later that day, it said, Stevens was scheduled to launch a project called "American Space Benghazi," a public outreach center containing a "small library, computer lab and open space for programming."
Editing by Warren Strobel and Todd Eastham