Axe-wielding thieves appear to have pulled off the biggest art heist in decades after they broke into one of Europe’s largest collections of treasures and made off with glittering objects valued at as much as $1 billion.

The daring robbery happened in the early hours of Monday in the German city of Dresden. Burglars forced entry to the Green Vault—housed in a former royal palace called the Residenzschloss—which has been the home of a historic collection of diamonds and other jewels for centuries.

Surveillance video released by German authorities showed the intruders using an axe to smash glass display cases to make off with hundreds of priceless artifacts in what police are calling the largest art heist since the Second World War.

The thieves—who reportedly escaped the scene in an Audi A6 and are now on the run—reportedly started a fire in the early hours of Monday that led to a power failure at the palace, disarming the elaborate network of security alarms. German media has reported the thieves then twisted back iron grill bars on a ground-floor window to gain access to the treasury’s historic collection.

Michael Kretschmer, the leader of Saxony—which has Dresden as its capital city—expressed his devastation at the historic heist. The minister said: “The treasures one can find there... have been collected by the people of Saxony over many centuries and are hard-won treasures... You cannot understand the history of our country, or the free state of Saxony without the Green Vault and the state art collections of Saxony.”

The Green Vault has been an international tourist destination since 1724, when it first opened to the public, according to The Guardian. It was heavily damaged during the Second World War during Winston Churchill’s controversial bombing campaign that destroyed the city of Dresden. The vault was successfully restored and there was a grand reopening in 2006.

Saxony state authorities have not given any details of what’s been taken from the vault or who they think might have been capable of carrying out the audacious raid. “We have not identified a perpetrator and nor have we yet made any arrests,” police spokesman Marko Laske said.

By good fortune, one of the collection’s best known treasures—the 41-carat Dresden “Green Diamond”—is currently on loan to New York City’s Metropolitan Museum of Art, so wasn’t there to be taken.

However, it houses thousands of other treasures, including a 648-carat sapphire that was a royal gift from Russian tsar Peter the Great; a golden coffee service made in 1701; and a 25-inch figure of a Moor encrusted with precious emeralds and other jewels.

Dozens of police cars are at the scene and the Green Vault is shut as the world’s media awaits further details of the theft.