Mocked-up images of a menacing hooded figure lurking behind Father Christmas have been circulated on ISIS-supporting messaging groups.
One, showing London’s Regent Street in the background, comes with the ominous caption “Soon on your holidays” in English, French and German, the Epoch Times reports.
Another shows a Christmas market in Paris, with the Eiffel Tower in the distance.
The sick messages were intercepted by BlackOps Cyber, an internet intelligence agency.
According to images provided by the company, it was shared at about midday on Thursday on a messaging group called Army of Mujahideen, which has at least 1,800 members.
The image was designed by a member calling himself Dr Almani, which itself could be a reference to a banned Twitter account whose bio said he was an “explosives warehouse official”.
Earlier this week six men, all of whom are originally from Syria, were arrested in Germany in connection with a suspected plot to attack a Christmas market.
Last year an ISIS-inspired terrorist killed 12 people after driving a lorry through a festive market in Breitscheidplatz in Berlin.
This week Express.co.uk reported that hundreds of ISIS fighters, after fleeing Syria are heading to the UK and Europe to mount a series of Christmas attacks.
The plots are suspected to have been hatched in retaliation to the group’s humbling defeat in its former stronghold, in the Syrian city of Raqqa.
A warning of the attack from Turkish intelligence officers follows concerns that the head of ISIS, Abu Bakr al-Baghdadi, escaped Raqqa with thousands of armed extremist fighters – including many British jihadis – in a secret peace deal five weeks ago.
A British military source, who attended the briefing, said this weekend that it left no room for doubt.
He said: “[The Turkish] intelligence service briefed that IS have been smuggled into Turkey in numbers and are heading to Europe and the UK.
“The threat level is very high and it is evident the Turkish authorities have detained a number of people and are confident the information is accurate.”
On Thursday security minister Ben Wallace confirmed IS continued to pose a grave threat to Britain.
And Middle East minister Alistair Burt added: “We know that Daesh (IS) will continue to pose a threat in the region.
“We also know that the battle of ideas is far from won, Daesh is still capable of inspiring people to carry out attacks in its name and, as such, it remains a serious global threat. We have seen tragic evidence of this on the continent, in the US and here in the UK.”