The West-hating militants are using Facebook and messaging app Telegram to gloat about Monday night’s Berlin terror attack.
One warned the terror group – also known as Daesh – is plotting to carry out another sick massacre over the Christmas period.
Hinting at more Berlin-style attacks using lorries and cars, they wrote: “The enemy can never stop this type of attack.
“You need nothing more than a vehicle, be it a truck or a car.
“With Allah, these operations leave the enemy frightened and terrorised.
“Who will crash into the next Christmas market, never let the kuffar (non-believers) forget this Christmas market o lions of Islam!”
And a Facebook user refused to mourn the dead, saying the 12 victims were “probably” critical of Islam. The user, whose profile claims he lives in Berlin, said: “They died as kafr.
“Go to hell so you do not need to mourn and it was probably the people who always criticise Islam anyway.”
And a popular Facebook page entitled ‘Islam Facts’ suggested the public outrage over the attack is disproportionate.
It said: “Hard to believe nine people [sic] are dying and the whole world stands up. “Just a reminder thousands of people die in Aleppo. Are the people of Germany more valuable?”
The comments come as German police ramp up their hunt for the suspect behind the Berlin attack, in which 12 people died.
Anis Amri, 23, arrived in Germany last year but officials failed to deport him when his asylum application was rejected.
He has previous convictions in both Tunisia – his birthplace – and Italy.