Thieves managed to disable an alarm and break through a balcony window to get inside the Greek National Art Gallery in Athens.
They got away with three valuable works.
One was a Picasso.
Another was by Piet Mondrian.
The third was an ink sketch by Guglielmo Caccia.
The raid took just seven minutes from entry to escape with the works of art which were removed from their frames.
They dropped a second Mondrian inside the gallery during their get away.
Police said in a statement they were chased by a guard but they weren't caught.
The National Gallery is home to one of the country's finest collections of Greek and foreign art.
It stands at a busy intersection in central Athens.
It has its own guards and police constantly patrol the area.
Paul Chapman, Reuters