FILE PHOTO: An Islamic State flag is seen in this picture illustration taken February 18, 2016. REUTERS/Dado Ruvic/Illustration/File Photo

CAIRO (Reuters) - A pro-Islamic State group on Wednesday urged supporters of the jihadists to carry out attacks on targets such as markets and hospitals in Europe over the Christmas holiday period and urged Muslims to stay away from Christian celebrations.

The threat came as European authorities have stepped up security following an attack claimed by 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 Islamic State, posted its message online, accompanied by images of fighters with guns and knives, Santa Claus, reindeer and a Christmas tree, according to the according to the U.S.-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 Islamic State would “replace their fireworks with explosive belts and devices, and turn their singing and clapping into weeping and wailing”.

The message reminded Islamic State supporters of a call earlier 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 Islamic State.