London police have detained 325 people during a demonstration supporting Palestine Action, a group banned in the UK. The number of arrests rose from 139 after officers updated their figures on the latest custody outcomes following the Saturday protest outside the US embassy in London. Most of those detained, 320 people, were arrested for allegedly supporting a banned organization under the UK’s Terrorism Act. Police said they did not explain why five people were detained. Earlier figures since the start of the campaign showed that people who carried a banner reading “I am against genocide, I support Palestine Action” had been detained since 5 July 2025. That banner-linked total has now reached 4,200 after adding the latest 320 arrests. Of the 4,200 people detained, around 2,500 are facing court proceedings. Their hearings are due to begin after a Wednesday appeal hearing at the High Court. UK High Court judges are set to start considering whether the ban on Palestine Action, announced on 4 November, is lawful. The ban was later challenged in court, and the High Court ruled on 13 February that the Home Office’s decision to ban the group was unlawful, but the ban was not lifted because the government was allowed to appeal. Palestine Action is known for actions targeting companies that do business with Israel. In June 2025, activists carried out an incident at RAF Brize Norton, cutting through perimeter fencing, entering the site, spraying red paint on aircraft engines, and leaving a Palestinian flag on aircraft. The Home Secretary at the time, Yvette Cooper, started the process that led to the group being banned in July 2025. Latest figures show 325 people are now in custody after Saturday’s action.