A pro-Isis group yesterday urged supporters of the jihadists to attack targets such as markets and hospitals in Europe over the holiday and urged Muslims to stay away from Christian celebrations.
The threat came as European authorities have stepped up security following an attack claimed by Isis (Islamic State) in which a truck ploughed into crowds in a Berlin Christmas market and killed 12 people this month.
The Nashir Media Foundation, which backs Isis, posted its message online, accompanied by images of fighters with guns and knives, Santa Claus, reindeer and a Christmas tree, according to the United States-based Site Intelligence Group, which monitors militant groups online.
"Their celebrations, gatherings, clubs, markets, theatres, cinemas, malls and even their hospitals are all perfect targets for you," the online message to Islamist "lone wolves" in Europe said.
It said Isis would "replace their fireworks with explosive belts and devices, and turn their singing and clapping into weeping and wailing".
The message reminded Isis supporters of a call this month by the group's new spokesman, Abu al-Hassan al-Muhajer, who said they should also attack Turkish consulates and embassies.
Turkey may have been chosen as a target because it has backed rebels in Syria against Isis and has also been fighting the group.
The Turkish military said yesterday it had "neutralised" 44 Isis militants and wounded 117 as part of its operation in the northern Syrian town of al-Bab.
The military also said seven rebels had been wounded in clashes over the past day, and 154 Isis targets had been struck by artillery and other weaponry.
Rebels supported by Turkish troops have laid siege to al-Bab for weeks under the "Euphrates Shield" operation Turkey launched nearly four months ago to sweep the Sunni hardliners and Kurdish fighters from its Syrian border.