Three armed men are being sought after paintings by Cézanne, Degas, van Gogh and Monet were stolen from a private museum in Zurich.
The paintings, which were stolen yesterday, have been valued at €112m.
They are: 'Poppies near Vetheuil' by Claude Monet (1879), 'Count Lepic and his Daughters' by Edgar Degas (1871), 'Chestnut in Bloom' by Vincent Van Gogh (1890) and 'Boy in a Red Waistcoat' by Paul Cezanne (1888).
Police in Zurich confirmed this afternoon that three armed men stole the paintings from the Buehrle Foundation museum on Sunday evening.
It is understood the men entered the museum at around 4.30pm local time and threatened staff with a pistol, before loading the paintings into a white van.
They drove off towards the suburb of Zollikon in the southeast of the city.
Police described the theft as the biggest ever robbery carried out in Switzerland.
Musem director Lukas Gloor said the stolen paintings were 'the four finest in the museum's collection'.
Mr Gloor said the paintings are so well known that it would be impossible to try to sell them on the open market.
The Buehrle museum was founded by German-born arms magnate Emil Buehrle.
It opened in 1960, and holds more than 200 paintings, including seven each by Van Gogh and Cezanne, six by Degas and five by Monet.
The theft comes days after thieves stole two paintings by Pablo Picasso worth €3m from a cultural centre in eastern Switzerland.
The two paintings were on loan to a cultural centre in the eastern town of Pfaeffikon.
