By Christina Marker, NBC NewsLONDON -- British police are investigating the defacing of a painting by Russian-American artist Mark Rothko at London's leading contemporary art museum.
The incident took place on Sunday when a visitor to Tate Modern (http://www.tate.org.uk/visit/tate-modern) applied "a small area of black paint with a brush to the painting," according to the gallery.
Photographs of the damage showed the text "VLADIMIR UMANETS '12, A POTENTIAL PIECE OF YELLOWISM'' scrawled on Rothko's 1958 canvas "Black on Maroon."
'Not art or anti-art'
Using a phone number posted on on the so-called "Yellowism" movement's website (http://www.thisisyellowism.com/), a Reuters journalist spoke to a man answering to the name Vladimir Umanets who said he carried out the attack.
NBCNews