An authorised firearms officer (AFO) is a British police officer who is authorised and trained to carry and use firearms. The designation is significant because most police officers in the United Kingdom do not routinely carry firearms, although they can be equipped with tasers. The only forces where officers are routinely armed are the Police Service of Northern Ireland, the Ministry of Defence Police, the Civil Nuclear Constabulary, Belfast Harbour Police and the Belfast International Airport Constabulary.