Armed bandits stormed a museum in Italy on Thursday and made off with 17 artworks, including masterpieces by Tintoretto, Rubens and Bellini, in one of the country’s biggest art heists, according to the Telegraph.

Thought to be a raid for a dubious private collector, one art expert even speculated it could be the work of jihadists looking to fund terror, reports the Daily Mail. Authorities noted that the artworks could not be sold for their value.

“It’s as if you broke into the Uffizi Galleries and stole a Botticelli. You couldn’t sell it on the open market,” said Tomaso Montanari, an art historian. “It’s certainly the most serious theft in the history of Italian art.”

The thieves ransacked the Castelvecchio Museum, a 14th-century fortress in Verona in northern Italy after hours, but before the alarms were activated. They tied up a guard and cashier, took the paintings and left in the guard's car.

"Male Portrait" by the Venetian artist Tintoretto, one of 6 works by the artist taken, are among the stolen works, estimated at about $16 million total. Also missing is an early Renaissance masterpiece titled 'Madonna of the Quail' by Pisanello, Andrea Mantegna’s “The Holy Family with a Saint,” Peter Paul Rubens’s “The Lady of Licnidi,” and two works by the Dutch landscape painter Hans de Jode. Six of the stolen artworks are considered of lesser value.

Police are examining footage from 48 security cameras around the museum. View a slideshow of the missing works on Repubblica.