This article is about an aircraft of World War I. For the pre-war design of the same designation, see Breguet Type IV.{| |} The Breguet Bre.4, also known variously as the Type IV and BUM, was a French biplane bomber of World War I. A fighter version of it also was produced as the BUC and BLC; some of these saw service with the British Royal Navy, which called them 'the Breguet 'de Chasse.