It's feared ISIS terrorists may try to smuggle 'materials, weapons or explosives' on to the sand to carry out a mass atrocity - like that committed on Bastille Day when 84 people were killed.
Cannes is a popular playground of the rich and famous - its annual festivals regularly attracting top celebrities like Bono, George Clooney and Cara Delevingne.
The ban covers promenades, boulevards and walkways around the marina where many of the luxury multi-million pound boats Hollywood stars stay in when in town are moored.
Mirror Online discovered that the local Mayor's office is now taking the extraordinary step of banning 'bags, suitcases and large luggage' - in a direct response to the terrorist threat.
Getty
It's feared those who break the rules 'could face arrest' by police - and tourists are being urged to carry 'see-thru' bags with them instead.
Getty
Earlier this month Mohamed Bouhlel, 31, drove in a lorry through crowds celebrating Bastille Day in Nice - killing 84 people - in an attack linked to ISIS.
Then just yesterday - a day after the memo was circulated - a French priest had his throat slit by two ISIS terrorists at a French church.
Getty
He revealed "from this morning" the ban extends not just to the beach but walkways on marinas and ports where luxury boats and other ships are moored.
Getty
He told NEPTUNEGIST Online that the measures had been issued by the Mayor's office at the Cannes Citadel - the equivalent of the Town Hall - "to protect tourists on the beaches".Cannes annonce interdiction sur les plages des sacs à dos, valises ou grands bagages pouvant dissimuler armes ou explosifs (jusqu'au 31/10)— Matthias Galante (@Matthiasgalante) July 27, 2016
Thomas Bazire said: "It's to forbid transport of big bags or luggage which could hide dangerous materials, weapons or explosives."
Getty
He added: "The police will inform everyone and will be vigilant.Depuis ce matin Cannes interdit, sur le bord de mer, le transport à pieds ou le port de grands contenants pouvant dissimuler armes/explosifs— Matthias Galante (@Matthiasgalante)
Getty
Mr Bazire said the best advice to tourists who were confused about the edict would be to "go to a policeman to see what they call big bags".
Getty
The Cannes Mayor's office confirmed the ban was true - but nobody was available for comment.
It's now been claimed the Bastille Day killer - described by ISIS as a "soldier of Islam" - regularly used dating websites to pick up male and female lovers.
French media reports that Mohamed Bouhlel's mobile phone records suggest he used the sites and dabbled with drugs and drink.
The mobile phone handset was recovered from inside the 19-tonne lorry he used to commit his mass slaughter on the Promenade des Anglais.
Seven suspects are currently being held in custody over their links to the terrorist.
Bouhlel is reported to have sent a chilling text message - demanding weapons - minutes before the massacre.
Investigations have focused on the wording: "Bring more weapons, bring five of them to C."
Bouhlel fired a 7.65mm automatic gun at police before they shot him dead.
More than 200 French police are now working on the case.
They have since discovered that he was spotted twice in the two days leading up to the attack driving the lorry - as he scouted out how best to execute the attack and maximise the number of casualities.