Police are hunting for a vandal who walked into the Tate Modern art gallery and defaced a valuable painting by Mark Rothko.
The visitor daubed black paint on "Black on Maroon" during a visit to the gallery yesterday afternoon.
Eyewitness Tim Wright posted on Twitter:
"This guy calmly walked up, took out a marker pen and tagged it. Surreal. We gave a description to the gallery. Very bizarre, he sat there for a while then just went for it and made a quick exit."
Earlier this year, Rothko's Orange, red, yellow was sold for £53.8 million - the highest price ever paid for a piece of post-war art at auction.
The 1961 painting went under the hammer at Christie's in New York.
More top news
Millwall fans who forced Barnsley supporters to flee as they tried to break into the opposing team's end at Wembley could face life bans.
Some sunny spells are likely later in the west following a dull start.
Young cancer sufferers got a surprise visit and were bowled over by One Direction's Niall Horan.