Lettow-Vorbeck thus withdrew to the south, with his troops on half rations and the British in pursuit. On 25 November 1917, his advance column waded across the Ruvuma River into Portuguese Mozambique. Having essentially cut their own supply lines, the "Schutztruppe" caravan became a nomadic tribe. On its first day across the river, the column attacked the newly replenished Portuguese garrison of Ngomano and solved its supply problems for the foreseeable future. The subsequent capture of a river steamer with a load of medical supplies, including quinine, satisfied some of its medical needs as well. For almost a year Lettow-Vorbeck's men had lived off whatever was available, mainly provisions captured from the British and Portuguese; they had replaced their old rifles with new equipment and acquired machine guns and mortars after capturing Namakura (Nhamacurra in modern Mozambique) in July 1918.