EU countries must monitor "very carefully" a growing threat from the Islamic State group in North Africa as militants relocate there from Iraq and Syria, the bloc's current presidency warned.
Estonian Interior Minister Andres Anvelt, whose country holds the six-month EU presidency, told AFP that with US and other foreign-backed forces driving IS fighters from their self-styled caliphate, many have relocated to North Africa in the last year.
"They are afraid to go back home (to Europe) because they have (committed) so-called war crimes or terrorist crimes. They are known," Anvelt said in an interview before chairing EU interior minister talks in Luxembourg on Friday.
"So they started to look for other places to fight and it's in North Africa. So we have to look very carefully what will happen in the close future in North Africa," said Anvelt.
"Daesh in North Africa is the second biggest problem after Syria and Iraq, where we have to put our efforts," he said, using the Arabic acronym for IS.
He cited concerns that IS cells could order attacks from North Africa, enter Europe from the region, or promote people smuggling as it is a good source of "tax" revenue.
He estimated that hundreds, if not thousands of IS fighters were now in North Africa, a presence that he said could fuel instability, particularly in Libya where EU and UN-backed Prime Minister Fayez al-Sarraj is struggling to restore order.
Such instability has been a major cause of migration to Europe and has divided the EU politically.
For around a year EU officials have also expressed concern about the risk of attacks from battle-hardened fighters returning from Iraq and Syria.
Anvelt gave no update on how many IS members have returned to Europe.
EU officials estimated in December that around a third of the estimated 5,000 European jihadists who went to Syria and Iraq have returned home.
But Anvelt said the Europeans have also benefitted from IS defeats in Syria and Iraq, as "battlefield evidence" and prisoner interrogations have helped "toward the preventing of terrorist attacks" in Europe.
He said civilian and military cooperation to gather evidence in war zones that can stand up in European courts is the trend toward fighting "the hybrid war" of terrorism.
Anvelt said IS has changed tactics in the last year or more by inspiring sympathisers through online propaganda to stage attacks with vehicles, such as in the French resort of Nice and the German capital Berlin, or knives, as in England.
Anvelt said European security experts were increasingly working with or aiming to work with the authorities in Libya, Niger, Tunisia, Algeria and Morocco to improve their security services as a mutual interest.
"So far Libya, as the most unstable country in this area, is the biggest concern for Europe," he added.
He said EU help in boosting the Libyan coastguard is one factor helping cut migration to Europe.
Anvelt meanwhile said he was concerned about Russia's alliance with General Khalifa Haftar in eastern Libya because, even if Moscow does not support IS, it may promote instability, a "push factor" for Europe-bound migrants.
"The Russian side over the last 10 years almost ... have not been very interested in cooperation," said the minister, whose former communist country is worried about Russia's new assertiveness.