 Complete the following phrase:  The German Askari in Burundi were forced to retreat by the numerical superiority of the Force Publique and by 17 June, Burundi and Rwanda were occupied. The Force Publique and the British Lake Force then started a thrust to capture Tabora, an administrative centre of central German East Africa. Three columns took Biharamuro, Mwanza, Karema, Kigoma and Ujiji. At the 