Twelve people have been arrested by counter-terrorism detectives in the UK due to fears of a Christmas bombing attack on British soil. According to police, the men, aged between 17 and 28, were held in Birmingham, Cardiff, London and Stoke-on-Trent on suspicion of the commission, preparation or instigation of an act of terrorism. After the arrests, police began searches at several properties, with detectives and forensic experts looking for evidence of materials that could be used to make bombs. The counter-terrorism operation targeting some of those arrested had been under way for some time, and is described as “significant”. The government’s assessment of the risk of a terrorist attack in the UK remains at “severe” the second-highest level meaning an incident is seen as highly likely.