In November 1940, Gazelle Force operated from the Gash river delta against Italian advanced posts around Kassala on the Ethiopian plateau, where hill ranges from bound wide valleys and the rainfall makes the area malarial from July to October. On 11 December, Wavell ordered the 4th Indian Division to withdraw from Operation Compass in the Western Desert and move to Sudan. The transfer took until early January 1941 and Platt intended to begin the offensive on the northern front on 8 February, with a pincer attack on Kassala, by the 4th and 5th Indian divisions, less a brigade each.