Police have launched an investigation after a painting of a politician, linked to the creation of Israel, was damaged.
Palestine Action said one if its activists had "ruined" a 1914 painting of Lord Balfour at Trinity College, part of the University of Cambridge.
A statement on the group's website said the painting had been "slashed" and sprayed with red paint.
Footage was also posted on social media.
A Cambridgeshire Police spokeswoman said: "This afternoon we received an online report of criminal damage today to a painting at Trinity College, Cambridge.
"Officers are attending the scene to secure evidence and progress the investigation. No arrests have been made at this stage."
Lord Balfour was foreign secretary in 1917 when a declaration was made pledging Britain's support for the establishment "in Palestine of a national home for the Jewish people" and has been seen by some historians as a starting point for the Arab-Israeli conflict.
