That is the view of international terrorism experts including Dr Jamie Shea, Nato's deputy assistant secretary general for emerging security threats, who warned a subsection of the terror group was intent on setting up “mega cells” in European cities.
Meanwhile, another group of ISIS fanatics are working intently on building a caliphate in the Middle East.
Speaking at the Security and Counter Terror Expo in London, the Nato chief said: “Some terror experts are worrying that ISIS may be splitting into two.
“One group that is trying to secure the remnants of the caliphate and the other aspect which is more setting up cells.
“One person referred to them the other day as mega cells across Europe which are able to effectively plan a regular number of attacks.”
A dedciated supply network would then operate between the two, ensuring European terrorists were well resourced with a steady stream of weapons and money.
Reports of a split in the extremist organisation first surfaced last year as the number of fighters loyal to its twisted cause rapidly grew.
ISIS was said to be gripped by a crisis of discipline as new recruits and veteran fighters tussled for power within the group.
Dr Afzal Ashraf, an expert in terrorism at the defence think tank Royal United Services Institute, agreed that a split in ISIS ranks looked increasingly likely.
He told media the division may involve the creation of “subordinate branches. One which looks at operations overseas and another branch that might include operations within its borders or on its borders”.
Effectively, ISIS could develop a ‘Foreign Office’ to deal with its violent extremism abroad while a Home Office-style department would concentrate on domestic affairs within the boundaries of the self-declared caliphate.
Dr Afzal added: “A split along leadership lines is less likely. But it is possible if a leader feels he is not getting enough airtime.
"Then he may decide to create his own reputation and so may decide 'we will support the Islamic State by being a semi-independent organisation that looks after its duty to attack the far enemy to prevent it from endangering the Caliphate’."
Dr Shea also warned there were “worrying signs” that ISIS was planning to reassert its position as the world’s most deadly terror group by “lashing out” on the West.
He told the conference: “As ISIS comes under pressure at home, the tendency is of course to show that it is still alive by lashing out, by launching spectacular attacks like in Brussels or Paris.”
Defence analysts estimate ISIS territory has been reduced by as much as a third in recent months.
While the group once controlled a population of some nine million Syrians and Iraqi’s, that has since fallen to around six million, in part thanks to daily bombing raids by the US-led coalition and Russian jets, Express reportred.
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