Louvre Remains Closed A Day After Brazen Jewelry Robbery — Authorities Probing Potential Organized Crime Links By Sean Neumann

The world-famous Louvre remained closed on Monday after a high-profile theft shocked the French museum’s security staff, which has reportedly become more vocal recently amid staffing concerns.

Thieves scaled the facade of the Parisian museum in broad daylight Sunday, using a ladder boosted by a mechanical boom truck and forcing a window open, smashing display cases inside, and making off with a handful of priceless jewels, PEOPLE previously reported.

Officials said the entire theft lasted less than 4 minutes and described the plot as a professional heist, according to the The Associated Press.

French authorities swarmed the museum in the 24 hours following, with photographs from outside the famed museum showing forensics investigators searching the scene for clues.

Paris Public Prosecutor Laure Beccuau said the heist is being investigated as potentially linked to “organized crime,” telling BFM TV the professional-grade heist could have been performed on spec for a high-profile art collector.

The theft occurred sometime between 9:30 and 9:40 a.m. local time after the museum had opened its doors, as visitors already strolled through the halls inside.

After lifting themselves up to a balcony outside the Gallery of Apollo, the thieves reportedly cut through glass windows with a battery-powered disc cutter to gain access to the museum. The BBC reported that the robbers then threatened guards waiting on duty and then stole items from two separate display cases. The robbers then fled on motorbikes.

The outlet reported that the thieves made off with eight priceless items, including diadems, necklaces, earrings and brooches – some of which had belonged to Napoleon Bonaparte’s wife, Marie-Louise, the Queen Hortense of Holland, French Queen Marie-Amelie, and a crown that belonged to Empress Eugenie, the wife of Napoleon III. The AP reported that Eugenie’s crown was recovered broken outside the museum, according to French authorities.

“It’s a major robbery,” Interior Minister Laurent Nunez said, according to the AP. The BBC referred to Sunday’s heist as the biggest in France since the Mona Lisa was stolen in 1911.

Sunday’s robbery took place 250 meters from where the Mona Lisa resides in the Louvre, according to the AP.

The robbery also took place amid ongoing strain among the museum’s security staff, the outlet reported.

“How can they ride a lift to a window and take jewels in the middle of the day?” one museum visitor asked the AP. “It’s just unbelievable that a museum this famous can have such obvious security gaps.”