Thieves broke into a Rotterdam museum on Tuesday and walked off with works from the likes of Picasso,Monet,Gauguin and Matisse potentially worth hundreds of millions. Police havent said how they pulled off the early-hours heist,but an expert who tracks stolen art said the robbers clearly knew what they were after. Those thieves got one hell of a haul, said Chris Marinello,who directs the Art Loss Register. The heist at the Kunsthal museum is one of the largest in years in the Netherlands. Its every museum directors worst nightmare, said Kunsthal director Emily Ansenk,who had been in Istanbul but returned immediately. Willem van Hassel,the museums chairman,said its security systems are automated,and do not use guards on site. Police arrived at the scene five minutes after an alarm was triggered,he said. He described the museums insurance as adequate for the exhibition. The collection was on display as part of celebrations surrounding the museums 20th anniversary. Police spokeswoman Willemieke Romijn said investigators were reviewing videotapes of the theft,which took place around 3 am local time,and calling for any witnesses to come forward. Art Loss Registers Marinello said the items taken could be worth hundreds of millions of euros if sold legally at auction. However,he said that was now impossible,as the paintings had been registered internationally as stolen. The stolen paintings include Pablo Picassos 1971 Harlequin Head; Claude Monets 1901 Waterloo Bridge,London and Charing Cross Bridge,London; Henri Matisses 1919 Reading Girl in White and Yellow; Paul Gauguins 1898 Girl in Front of Open Window; Meyer de Haans Self-Portrait,around 1890. Marinello said the thieves had limited options,such as seeking a ransom from the owners,the museum or the insurers. They could conceivably sell the paintings in the criminal market too,though any sale would likely be a small fraction of their potential auction value. Thieves with an eye for art Heists over the years Heres a look at some top art heists over the decades MIDNIGHT IN PARIS In May 2010 at Paris Museum of Modern Art,a masked intruder made it look as easy as 1-2-3. Taking advantage of a broken alarm system,the thief stole a Picasso,a Matisse and three others worth $123 million. The case remains unsolved. SWISS JOB Zurich police called it an entirely new dimension in criminal culture. In February 2008,three men entered the Buehrle museum half-hour before closing on a Sunday. While one used a pistol to force personnel to the floor,the two others went and collected four paintings by Cezanne,Degas,van Gogh and Monet worth $163 million. APPEARANCES ARE DECEPTIVE In March 1990,two thieves dressed in police uniform fooled staff at the Isabella Stewart Gardner Museum in Boston to pull off the biggest art theft in US history. The pair made off with some $300 million in art. The paintings remain missing. It remains the largest single property theft of all time. BROAD DAYLIGHT In August 2004,two Edvard Munch masterpieces,The Scream and Madonna,were stolen from Munch Museum in Norway in a daylight raid. The paintings were found two years later. MONA LISA AINT SMILING Its a heist that helped create the celebrity status that Mona Lisa wields to this day. In August 1911,Leonardo da Vincis enigmatic masterpiece was taken brazenly from Pariss Louvre museum. Pablo Picasso was among those detained and taken in for questioning. It took two years to discover the real thief: a Louvre employee called Vincenzo Peruggia.