In Portuguese and South African service it was used in combat in the First World War and in several colonial campaigns. The German colonial troops in East Africa also used Mauser–Vergueiro rifles, captured from the allied forces in combat. The Portuguese Expeditionary Corps on the Western Front used British weapons and equipment for logistical reasons, and so did not use the Vergueiro. Although Portugal was neutral in World War II, in 1942 Portuguese forces briefly fought against the Japanese occupation of Portuguese Timor using Kropatschek rifles