North African officials say a large number of foreign recruits who joined the Islamic State in Syria and Iraq have returned to their countries and remain loyal to the extremist organization. They fear the returnees are planning to unleash terrorist attacks in the coming months, adding to a jihadist menace that includes well-entrenched al-Qaida affiliates.
African Union officials estimate about 6,000 Africans who fought for IS either have returned home already or are en route.
Not all will continue with their militancy or engage in insurgency — a large number may have become disillusioned or exhausted by conflict, say analysts. Nonetheless, many will re-engage, adding to alarm over a burgeoning security challenge that was underlined last month in Egypt with a mass bomb-and-gun attack on a mosque in North Sinai that left more than 300 people dead.
Analysts say North African governments have had some success in containing extremist threats. Without better coordination between them, however, they risk merely shifting the danger and allowing militants, who view their insurgency as regional rather than country-specific, to use national borders, over which there are weak state controls, to their advantage.
The states whose territory jihadists operate in need "to become more formidable in governing their vast swaths of land and securing their borders," an analysis by the Foundation for the Defense of Democracies, a Washington-based think tank, argued this month.
But securing coordination between governments that are suspicious of each other and frequently feud is another matter.
Egypt has seen increased militant activity in the western desert, with arms and fighters easily crossing into the country from strife-torn neighboring Libya. The western desert has become yet another front for Egyptian security forces, already hard-pressed to contain an IS affiliate in the Sinai, which according to Beverley Milton-Edwards, an analyst with the Brookings Doha Center — a think tank — is an ungovernable space.
"Sinai has been unmanageable for years, if not decades," she said.
So-called ungovernable spaces provide a place from which to generate myriad illicit income streams for the jihadists, allowing them to raise funds from extortion and kidnappings for ransom, along with human trafficking and contraband smuggling.
The FDD in a recent analysis calculated that AQIM has reaped about $100 million through a combination of ransom, drug smuggling, taxes on locals and donations from rich Gulf supporters.
And across North Africa, a series of ungovernable spaces have created a jihadist corridor for the movement of fighters and weapons, the biggest of which is Libya, a boat ride from the southern shores of Europe and riven by rival governments and militias, where IS fighters also have been flocking.
"The foreign fighters are fleeing and heading home under their own steam," warned Italy's Interior Minister Marco Minniti in a speech last month at Rome's advanced police training academy.
He added, "The danger exists that North Africa can become a refuge [for terrorists] and not just a transit point but a base from which to launch attacks."
Ties to North Africa have linked several of the recent terror attacks seen in Europe, and European counter-terror officials say they are perturbed by the increasing number of attacks that feature links to North African jihadists or affiliates of either IS or al-Qaida.
The suicide bombing earlier this year at a Manchester concert was mounted by British-born Salman Abedi, whose parents are Libyan. He traveled frequently to Tripoli to visit relatives and may have had terrorist training there.
Two of the three London Bridge attackers in June also were from North Africa. Rachid Redouane claimed variously to be Libyan or Moroccan, and Youssef Zaghba was born in Morocco.
It was a Tunisian, whose asylum application had been declined, who drove a truck into a crowded Christmas market in Berlin in December last year, an act of terrorism that left 12 dead.
And the assailants in the attacks in Barcelona in August that left 14 people dead, the worst act of jihadist terrorism in Spain since 2004, had North African links.
Last week, testifying before a U.S. Senate panel, the U.S. coordinator for counterterrorism, Nathan Sales, warned that jihadists are developing networks across North Africa in the wake of the collapse of IS in Syria and Iraq, posing a threat not only to the region, but to nearby Europe.
He argued that the brutal and long insurgency waged in Algeria by the Groupe Islamique Armé (GIA) in the "black decade" of the 1990s underscored the risks posed by returning terrorist fighters.
"We also remain concerned about al-Qaida's affiliates in the region, especially al-Qaida in the Islamic Maghreb [AQIM], and their growing reach into other parts of Africa", Sales told the panel.