P ARIS and LONDON -- Several people disguised as construction workers broke into the world-famous Louvre museum in Paris on Sunday, cracking open display cases and stealing jewelry that once belonged to the Emperor Napoleon and his wife, officials said.

The museum was closed Sunday after the robbery, which was carried out by thieves using a ladder mounted on the back of a truck, officials said.

The Louvre Museum in Paris has been forced to close while police investigate a brazen heist which reportedly targeted France's priceless crown jewels. Thieves wielding power tools broke into the world's most visited museum in broad daylight, before escaping on scooters with items said to be of "incalculable" value.

Other items in the Louvre that belonged to the Empress are diamond brooches, among them this piece from 1855. It is called a reliquary brooch, although the Louvre says that the diamond-clad item does not contain any spaces to house a holy relic.