"Not only the state art collections were robbed, but we Saxons," tweeted the prime minister of Saxony.
Thieves targeted a world-renowned museum in Dresden, taking an "unimaginable" amount of treasure, the museum said in a press conference on Monday.
Two suspects caught on surveillance video were filmed entering the Grünes Gewölbe museum, or Green Vault, after bending back a metal grille and breaking the glass.
They then targeted multiple display cases which held three large sets of jewelry containing multiple diamonds, the museum director said. After appearing to target the jewelry displays, they fled the museum by car.
The collection, located in a former royal palace, was founded in the 18th century by August the Strong, Elector of Saxony and later King of Poland to show off objects from the treasury.
Police, who were first informed of the heist around 5 a.m. on Monday (11 p.m. ET Sunday), have not ruled out the involvement of other suspects outside the museum. A burned car was found in the area and police are investigating if there is a connection to the robbery.
Investigators are still on site and cannot say yet if all the pieces were stolen or if some were left behind.
They are also investigating a nearby fire that led to a power outage in the area to see if there is a connection.
Seventeen objects from the museum are currently on loan to New York's Metropolitan Museum of Art, including one of its best known pieces, a hat ornament featuring the 41-carat Dresden Green Diamond.
The Grünes Gewölbe museum, or Green Vault, said on its website that it was closed for "organizational reasons" on Monday. It is part of the Staatliche Kunstsammlungen Dresden, or state art collection.
"Not only the state art collections were robbed, but we Saxons," tweeted Michael Kretschmer, the minister-president of Saxony, the Germany state where Dresden is located.
"The values found here have been hard-won by the people of our free state for many centuries," he added.
Carlo Angerer reported from Mainz, Germany, and Rachel Elbaum from London.