LONDON — Priceless paintings by Monet, Cezanne, Van Gogh and others were unharmed Saturday after firefighters worked to douse a blaze that broke out in the roof of Somerset House, a large central London arts venue, officials said.

Heavy smoke and flames seen coming from the top of the historic building around noon had been knocked down by firefighters who poured water on it from buckets on ladder trucks.

Firefighters were working to extinguish the final pockets of flames in the early evening…