London police said Sunday that 532 people were arrested the previous day when supporters of a pro-Palestinian group that was recently outlawed as a terrorist organization intentionally broke the law.

British police said they arrested 365 people in central London on Saturday as supporters of a recently banned pro-Palestinian group intentionally defied the law as part of their effort to force the government to reconsider the ban.

Police in London have detained more than 466 people who were protesting the United Kingdom’s decision to ban the Palestine Action Group, marking the “largest ever mass arrest” at a single protest in the British capital, according to campaigners.