A lone thief stole five paintings valued at a total of half a billion euros, including works by Picasso and Matisse, in a brazen overnight heist Thursday from a Paris modern-art museum, police and prosecutors said.

The paintings were reported missing early Thursday from the Paris Museum of Modern Art, across the Seine River from the Eiffel Tower, according to Paris police. Investigators have cordoned off the museum in one of the French capital's most tourist-frequented neighborhoods.