In a brazen, daylight strike, thieves used a basket lift to reach the Louvre on Sunday morning and, as tourists were already inside, forced open a window, smashed display cases and fled with jewels of “inestimable value,” France’s interior minister says.

The world’s most visited museum closed for the day as police sealed gates and ushered visitors out during the investigation.

“A robbery took place this morning at the opening of the Louvre Museum,” Culture Minister Rachida Dati wrote on X. The museum cited “exceptional reasons” for the closure. No injuries were reported.

Around 9:30 a.m. local time several intruders forced open a window, stole jewels from vitrines and escaped on two-wheelers, according to the Interior Ministry. It said forensic work is underway and a precise inventory of the stolen objects is being compiled, adding that the items have “inestimable” historical value.

Video from the scene showed confused tourists being ushered out of the glass pyramid and surrounding courtyards as officers shut the iron gates and closed nearby streets along the Seine.

Interior Minister Laurent Nuñez called it a “major robbery,” saying the intruders entered from the outside using a basket lift. He said on France Inter radio that the heist took seven minutes and the thieves used a disc cutter to slice through the panes. He said it was “manifestly a team that had done scouting.”

The heist occurred in the Galerie d’Apollon, a vaulted hall in the Denon wing that displays part of the French Crown Jewels beneath a ceiling painted by King Louis XIV’s court artist, according to the ministry.

French daily Le Parisien reported the thieves entered via the Seine-facing facade, where construction is underway, and used a freight elevator to reach the gallery. After breaking windows, they reportedly took nine pieces from the jewelry collection of Napoleon and the Empress. One stolen jewel was later found outside the museum, the paper reported, adding that the item was believed to be Empress Eugénie’s crown and that it had been broken.

Security around marquee works remains tight. The Mona Lisa is protected by bulletproof glass and a custom high-tech display system as part of broader anti-theft measures across the museum.