The move comes following the recent terror attacks in the country
The city's mayor says the new rule, which will remain in effect until the end of October, is designed to stop bags "that could contain explosives or weapons" and allows police "to intervene in a pragmatic way".
Violators could be fined or asked to leave the beach under the new measures.
The decision comes as French authorities face serious questions about the state of security in the country.
France remains in a state of emergency after 84 people were killed when a jihadist ploughed a lorry through a crowd celebrating Bastille Day in the nearby city of Nice.
A probe found that police presence was "not undersized" at the time of the attack, though pressure on the government has intensified after it emerged that two men who killed a priest in his church in Normandy were known to security officials.
DNA tests have confirmed the second man in the attack as Abdelmalik Petitjean, who had been on a terror watch list since June 29th after Turkish officials spotted him at an airport heading to Syria. For unknown reasons the 19-year-old returned to France.
On July 22nd, four days before the church assault, the French anti-terror organisation Uclat issued a photo of an unnamed man - who turned out to be Petitjean - warning that the person "could be ready to participate in an attack on national territory".
Opposition politicians have voiced strong criticism of the government's security record, with potential presidential candidate Nicolas Sarkozy calling for the detention or e-tagging of all militant Islamist militants.
The so-called Islamic State has released a video of Petitjean and his accomplice, Adel Kermiche, purporting to show the pair pledging their allegiance to the group.
Kermiche, who had also previously attempted to travel to Syria, was awaiting trial on terror charges and had been fitted with an electronic tag, despite calls from the prosecutor for him not to be released.
The French government has announced that 10,000 military personnel, deployed after an attack in January 2015, will be spread out more around areas outside Paris.
Interior minister Bernard Cazeneuve has said that public events should be cancelled "if conditions do not allow for optimal security".
Several French media outlets have taken the decision to stop showing pictures of attackers after the recent attacks, and opposition lawmakers have submitted a draft bill that would prohibit the identities of militants being revealed in order to prevent their names being glorified.