evidence: In London more than 1,000 police officers were deployed as crowds marched from the BBC's New Broadcasting House to Downing Street. [...] The London protest began at the BBC's headquarters in Portland Place, which was vandalised overnight with red paint splattered over the building's entrance. In a social media post later on Saturday, activist group Palestine Action claimed responsibility for daubing the building in "blood red paint, symbolising their complicity in Israel's genocide of the Palestinian people through biased reporting".