Security protocols failed in preventing a major jewellery heist at the Louvre museum in Paris, leaving the country with a terrible image, France's justice minister has said.
Thieves wielding power tools broke into the world's most-visited museum in broad daylight on Sunday, stealing eight items described as of inestimable value, before escaping on scooters.
Security measures have been tightened around France's cultural institutions, advisers for the country's interior minister said.
There are fears that, unless the thieves are caught quickly, the priceless items, including a diamond and emerald necklace Emperor Napoleon gave to his wife, will be broken down and smuggled out of the country.
The Louvre announced it would remain closed on Monday while investigations continued.
French media reports that a preliminary assessment by the Court of Auditors (due to be published in November) found that a third of the rooms in the wing where the robbery took place have no surveillance cameras.
What is certain is that we have failed, since people were able to park a furniture hoist in the middle of Paris, get people up it in several minutes to grab priceless jewels, Justice Minister Gérald Darmanin told France Inter radio.
He added that he was certain police would eventually arrest the thieves.
However, the head of an organisation specialising in the location and recovery of stolen artworks warned that if the thieves were not caught in the next 24-48 hours, the stolen jewellery would likely be long gone.
There is a race going on right now, Chris Marinello, the chief executive of Art Recovery International, told the BBC World Service.
Crowns and diadems - which were stolen in the heist - can easily be broken apart and sold in small parts. The thieves are not going to keep them intact; they are going to break them up, melt down the valuable metal, recut the valuable stones, and hide evidence of their crime, he warned.
The robbery took place between 09:30 and 09:40 local time on Sunday morning, shortly after the museum opened to visitors. Four masked thieves used a truck equipped with a mechanical lift to gain access to the Galerie d'Apollon via a balcony close to the River Seine.
Two of the thieves cut through glass panes with a battery-powered disc cutter and entered the museum, where they threatened the guards, evacuated the building, smashed glass display cases, and made off with the jewels in around eight minutes.
Among the stolen items were an emerald and diamond necklace gifted to Empress Marie Louise by Napoleon, and a jewel-studded tiara that belonged to the Empress Eugénie, wife of Napoleon III.
Following the incident, French President Emmanuel Macron condemned the theft as an attack on national heritage, while the culture ministry confirmed that museum protocols were followed during the incident.