Paris (CNN) -- An armed robber held up a jewelry exhibition in the French resort city of Cannes on Sunday, stealing jewels worth $53 million (40 million euros), a Nice police official told CNN on the condition of anonymity.
The robbery -- the third such heist around the city since May -- took place Sunday morning at the Carlton Hotel, according to Philippe Vique, deputy prosecutor for organized crime in the prosecutor's office for the Provence-Alpes-Côte d'Azur region. He could not confirm the value of the jewelry.
The robber, whose face was covered by a hat and a scarf, threatened to shoot the exhibitors and guests, Vique said.
Security guards were present but unarmed, he said.
The exhibitor, Leviev Extraordinary Diamonds, confirmed the heist and said it was "relieved that no one was injured in the robbery."
The gems were supposed to have been on display until the end of August.
The robbery follows two major jewel heists this year at events tied to the Cannes Film Festival.
During the festival in May, a necklace worth $2.6 million (2 million euros) was stolen from a hotel party shortly after more than $1 million worth of jewels were stolen from a safe in a hotel room.
Jeweler de Grisogono said the necklace was part of a collection making its debut.
The jewels were from the Swiss firm Chopard, which was sponsoring the festival.
The high-profile thefts follow a brazen heist in neighboring Belgium in February. Eight masked, heavily armed men used two vehicles to burst through a hole in the perimeter fence at Brussels Airport and nabbed $50 million in rough and polished diamonds from the hold of a Zurich-bound aircraft before speeding away. More than 30 arrests have been made in that incident.
And in 2008, four armed robbers -- two disguised as women -- walked into luxury jeweler Harry Winston's store on Paris' famed Champs Elysees and swiped an estimated $111 million worth of merchandise in the span of 15 minutes. Those gems were found in 2011, hidden in a rain sewer at a house in the Parisian suburb of Seine-Saint-Denis.
CNN's Stephanie Halasz, Vladimir Duthiers and Lauren Russell contributed to this report.