More than 20 people have been arrested during a protest in London in support of Palestine Action, a group which has been banned under UK anti-terrorism laws.

Under UK laws, offences include inviting support, expressing approval, or displaying symbols of a banned group and are punishable by up to 14 years in prison and/or a fine. Britain has proscribed 81 groups under anti-terrorism laws, including Hamas, al-Qaeda and ISIS.

Metropolitan Police arrested at least 27 protesters who gathered in central London on Saturday to publicly support Palestine Action, a nonviolent direct action group now officially designated a terrorist organization by the U.K. government.