Jewellery sets of diamonds and rubies were stolen from Dresden's Green Vault museum, one of the world's oldest museums, containing priceless treasures and jewels, German officials said on Monday.

The treasury of Augustus the Strong of Saxony was established in 1723 and today contains around 4,000 objects of gold, precious stones and other materials on display in the historic palace.

The governor of Saxony, where Dresden is located, said the vault contained items collected over many hundreds of years.

"It's not just the State Art Collections that was robbed, but us Saxons," Michael Kretschmer tweeted. "One can't understand the history of Saxony without the Green Vault."

Multiple burglars forced their way into the building in the early morning hours, and authorities were still trying to assess the losses, Interior Minister Roland Woeller told reporters.

The thieves "stole cultural treasures of immeasurable worth — that is not only the material worth but also the intangible worth to the state of Saxony, which is impossible to estimate."

German media reported the losses from the early-morning burglary could run into the high hundreds of millions of euros. Police said it was too early to estimate the value of the items stolen but planned to provide further information over the course of the day.

Woeller said police had already set up a special team of investigators to pursue the case. "We will do everything in our power not only to bring the cultural treasures back, but to capture the perpetrators," he said.

Exhibition rooms at the museum include focus on treasures featuring jewels, ivory, silver and amber among other objects.

One of its most famous and precious treasures, the Dresden Green Diamond, is currently on loan with other valuable pieces to the Metropolitan Museum of Art in New York for an exhibit.

The 41-carat green diamond was acquired by Augustus III, the son of Augustus the Strong, in 1742, according to the museum. 

The museum didn't put a current value on the piece, but said at the time of its purchase it cost 400,000 thalers, compared to the 288,000 thalers it cost to build Dresden's lavish Frauenkirche church at around the same time.

(With input from AP and AFP)