The attack killed three, with one woman beheaded by the twisted terrorist
Tunisian group al-Mahdi posted a film boasting they "prepared the young man for the attack in Nice" and "provided him with the logistical means".
They also threatened the French president, saying: "As long as Macron's dog continues to caricature the prophet, we still have a large number of warriors to avenge the faithful."
Grinning suspect Brahim was able to move from Tunisia to France virtually undetected
The murders followed the publication of cartoons of the Prophet Mohammed by satirical magazine Charlie Hebdo.
Mr Macron has since provoked fury in the Muslim world after refusing to condemn the cartoons.
ISIS terror chiefs called for "revenge" for the cartoons.
Little-known Jihadist group al-Mahdi is thought to have links to Islamic State, as well as al-Qaeda.
The suspected attacker, Brahim Aoussaoui, 21, arrived in Europe just weeks before launching Thursday's bloody attack, using a foot-long knife to butcher his victims.
A security source told the Parisien newspaper that Aoussaoui had followed the "classic migratory route" to Europe from North Africa, and arrived on the Italian island of Lampedusa on a small boat on September 20.
"The young man was then suspected of having contracted Covid-19 and was placed in solitary confinement on a ship," said the source.
According to the source, Aoussaoui should have been jailed before deportation after disembarking on October 9 in the port of Bari with no papers and clearly suffering health problems.
He then made his way to Paris, and then to Nice, travelling by train in a manner that did not alert officials.
An investigation is currently underway to "determine the causes of this dysfunction," the source reported.
An armed society is a polite society.
The only reason that the US hasn't followed in Europe and UK's footsteps on both socialization and disarming of citizens is our wonderful Constitution!
R.C.