Moderate Islamists who were harshly suppressed by secular Arab dictators have gained political power or prominence following popular uprisings in Tunisia, Libya and Egypt.

But armed, militant Islamist groups, including the North African wing of al Qaeda, have also benefited from lapses in internal security across the region wrought by the often chaotic transition to more democratic government.

Marzouki told pan-Arab daily al Hayat that some of Tunisia's hardline Salafists had links to al Qaeda and that North African countries would work before the end of the year to form a united front against the threat of rising Islamist militancy.

"The centre of the terrorist movement is moving now from Afghanistan and Pakistan to the Arab Maghreb region ... and the great danger is at our doors," Marzouki said.

He said around 3,000 Salafists in Tunisia were estimated to be potentially dangerous and described them as a "cancer" in the country, the first in the Arab world to bring down dictatorship in a wave of popular uprisings.

Marzouki, a secularist in office under a power-sharing deal with the moderate Islamist Ennahda party after it won a free election a year ago, said talks with such militants were futile and the threat they posed must be addressed with legal measures.

SECURITY VACUUM

"(Militants) are mainly present in Libya and Algeria, and especially in the south," Marzouki said, referring to the remote and thinly populated desert expanses of the Maghreb where policing is weaker and there has been traditional tribal resistance to central authority.

"There is a security problem now threatening the entire Arab Maghreb region ... All our southern borders are threatened with this problem now. There has to be a unified response from all the countries."

Last month, Salafists predominated in a crowd of protesters who ransacked the U.S. embassy in Tunisia in fury over a film insulting the Prophet Mohammad, killing two people, and the U.S. ambassador to Libya was killed in an Islamist militant ambush.

Al Qaeda's affiliate in North Africa then urged Muslims to kill more U.S. government representatives in the region - particularly in Libya, Tunisia, Morocco and Mauritania.

AQIM, or Al Qaeda in the Islamic Maghreb, emerged out of Algeria's civil conflict but has gradually expanded south into the Sahara and raised its profile in recent years with hit-and-run attacks and kidnapping of Westerners for ransom.

There have been no Arab Spring-style revolts in Algeria or Morocco. But Algeria's government has long clashed with Islamist militants particularly from AQIM on its territory while Morocco has suffered occasional fatal bomb attacks.

Marzouki also said that Arab peacekeeping forces should enter Syria to prevent chaos in a transitional period if Syrian President Bashar al-Assad succumbed to an uprising now in its 18th month. "(Assad's) regime is finished and dead, and we must move now. Syria could enter a stage of overwhelming chaos."

Rivalries among world and regional Arab and Muslim powers have prevented effective foreign intervention in Syria's conflict.

(Reporting by Shaimaa Fayed; Editing by Mark Heinrich)

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