Thieves have snatched five masterpieces worth some 100 million euros from the Museum of Modern Art in Paris.
The paintings were stolen late on Wednesday and reported missing on Thursday morning.
Police have now cordoned off the museum just opposite the Eiffel Tower on the banks of the Seine.
The five missing works include Le pigeon aux petits pois by Pablo Picasso; La pastorale by Henri Matisse; L’olivier pres de l’Estaque by Georges Braque; La femme a l’eventail by Amedeo Modigliani; and Nature morte aux chandeliers by Fernand Leger.
Sources close to the investigation say the theft is one of the biggest in art history.