Thieves pull off daring daylight jewelry heist at the Louvre

French authorities are investigating an elaborate daylight jewelry heist at the Louvre Museum in Paris.

(CNN) – French authorities are investigating an elaborate daylight jewelry heist at the Louvre Museum in Paris, one of the most famous and heavily visited museums in the world.

Officials say thieves made off with what they describe as “priceless” jewelry from the museum’s Apollo Gallery, home to the French Crown Jewels and other royal treasures.

“It does appear that these were extremely well-trained robbers,” said Ariel Weil, mayor of Paris Centre. “They planned this meticulously, obviously.”

The robbery took place around 9:30 a.m. Sunday, just 30 minutes after the museum opened to the public. Authorities say the thieves raided the gallery in only seven minutes before fleeing on motorcycles.

Investigators believe the crew entered through an external freight elevator mounted on a truck, then forced open a window to gain access to the gallery. Officials have not yet released a list of the stolen items or their estimated value.

Located near the room that houses the Mona Lisa, the Apollo Gallery features royal artifacts including Louis XIV’s hardstone vessel collection.

Tour guide Ryan el Mandari recalled the confusion inside the museum as the theft unfolded. “Nobody knew what happened,” he said. “We heard the sounds and we had no clue that it was a robbery.”

The Louvre, the largest art museum in the world with more than 750,000 square feet of exhibition space, welcomes over 8.5 million visitors annually. Following the break-in, museum officials evacuated guests and closed the building as police began their investigation.

“It’s a pity, but I think that when this is so exceptional, they can’t do anything about it,” said one visitor. Another added, “It takes a while to get the tickets to get in here, so it’s a little disappointing.”