EXCLUSIVE: Intercepted ISIS Message Reveals Threat to Attack London Over Christmas

A sign that reads "No Terror" lies on candles and flowers at a memorial for the Christmas market terror attack victims at Breitscheidplatz in Germany on Jan. 19, 2017. On Dec. 19, 2016 Anis Amri, a Tunisian radical, drove a heavy truck into a crowded Christmas market at Breitscheidplatz, killing 12 people and injuring 50. Steffi Loos/Getty Images

LONDON—The ISIS terrorist group could be planning to attack London over Christmas, as revealed by a chilling image intercepted from a terrorist instant messaging chat.

In the image, a black-clad hooded figure is seen standing over a kneeling Santa Claus with an image of the Regent Street shopping area in the background.