A pro-Palestinian UK protest group on Friday said one of its activists had "ruined" a portrait on display of Arthur Balfour, the British politician whose declaration helped lead to Israel's creation.

Police confirmed officers had received an online report of criminal damage to a painting at the University of Cambridge's Trinity College, in eastern England.

Palestine Action, which describes itself as a direct-action network of groups and individuals, said it was responsible for damaging the 1914 painting of the statesman.

It posted video footage online of the activist spraying the artwork with red paint from a cannister and then slashing the surface of the framed painting multiple times.

The group said the targeted artwork was a portrait of Balfour -- the UK's foreign secretary in the early 20th century -- by Hungarian-born artist Philip de Laszlo.

"Palestine Action spray and slash a historic painting of Lord Balfour in Trinity College, University of Cambridge," it wrote on X, formerly Twitter, alongside the 11-second video of the vandalism.

The post accused Balfour of beginning "the ethnic cleansing of Palestine by promising the land away -- which the British never had the right to do".

The Balfour Declaration was a 67-word letter in 1917 from Britain's then-foreign secretary to Lionel Rothschild, a prominent British Zionist, supporting the creation of a Jewish homeland in Palestine.

The document is credited with eventually helping to spur the creation of Israel in 1948, which also led to the displacement of around 750,000 Palestinians and decades of strife between the two communities.

Trinity College said it "regrets the damage caused to a portrait of Arthur James Balfour during public opening hours".

"The police have been informed," it added, noting "support" was being made available to any member of the college community impacted.

Cambridgeshire Police said officers were "attending the scene to secure evidence and progress the investigation", a statement added, noting that no arrests had been made.

Palestine Action has been involved in large-scale pro-Palestinian protests in London over recent months, in response to the ongoing war in Gaza.

The demonstrations have been heavily criticised by Prime Minister Rishi Sunak's ruling Conservatives, and others, for being intimidating to Jewish people and encouraging anti-Semitism.

Members of Palestine Action sprayed a building in central London on a march route with red paint during at least one protest in October.

They have also staged other "direct action" stunts at the sites of UK companies that the group claims are complicit in providing finance and military parts to Israel.