And most frighteningly of all – terror experts have backed up the chilling claims.
During the migrant crisis it was feared jihadists could sneak through the European Union’s porous borders as thousands arrived into the continent daily from war-torn nations.
This included in July, Mohammad Daleel, a 27-year-old failed asylum seeker, who blew himself up outside a party in Ansbach, Germany.
ISIS later said he was a “soldier of the Caliphate”.
But now Express.co.uk has seen online material from ISIS supporters, claiming sleeper cells are waiting to attack.
One ISIS supporter boasted over Telegram app about upcoming attacks which he claimed would be as deadly as those in Nice and Paris.
He said: ”There are many cells being set up.
“That Islam will bring fear upon their land and each home.
“And many more attacks are carded.
“And on the way in many forms and fashions.