In London, around 400 people gathered for a rally outside British Broadcasting Corporation (BBC) offices to protest the media giant’s refusal to broadcast a charity appeal to raise emergency funds for people in Gaza.
The crowd was addressed by speakers including Tony Benn, a former Labour cabinet minister, and George Galloway, an MP, who accused the BBC of bias against the Palestinians.
The protesters chanted "BBC, shame on you" and a few threw shoes at the BBC office.
The numbers later swelled to at least 5,000 for a march through central London.
The Stop The War Coalition, which organised the march, estimates that the ban on broadcasting the appeal could cost up to $14 million in donations.
The group had organised big rallies opposed to the violence in Gaza in London over the past few weekends.
Around 5,000 people also took to the streets of Birmingham, Britain's second biggest city, for a pro-Palestinian demonstration, while around 100 Cambridge University students have occupied the law faculty there in protest at Israel's attacks on Gaza.