Lettow-Vorbeck's guerrilla warfare compelled Britain to commit significant resources to a minor colonial theatre throughout the war and inflicted more than 10,000 casualties. Eventually, the weight of numbers, especially after forces coming from the Belgian Congo had attacked from the west (Battle of Tabora), and dwindling supplies forced Lettow-Vorbeck to abandon the colony. He withdrew south into Portuguese Mozambique, then into Northern Rhodesia where he agreed to a ceasefire three days after the end of the war after receiving news of the armistice between the warring nations.