Seven paintings, including works by Picasso, Matisse, Monet and Gauguin, were stolen from Rotterdam's Kunsthal overnight, police said Tuesday, after initially declining to identify the art.

"On Tuesday morning seven artworks were stolen from the Kunsthal in Rotterdam. In consultation with the owners the police can now release their photos," a police statement said, accompanied by the images.

"There was a break-in during the night and a few paintings were taken that represent a considerable sum," Rotterdam police spokeswoman Patricia Wessels told AFP.

"A major investigation is underway and forensics are at the scene," she said, adding that "for several reasons we can't say yet which works are concerned or which artists."

One of the stolen paintings is likely by French artist Henri Matisse, the ANP news agency said, as one of its photographers took a picture early Tuesday of a broken wire hanging from the wall where one of his paintings had been.

"We're investigating how they got access, what time it happened and who did it," Wessels said.

The museum is showing works from the Triton Foundation as part of its 20th anniversary celebrations, including paintings by Pablo Picasso, Vincent Van Gogh, Marcel Duchamp and Piet Mondriaan, according to its website.