Japanese air attacks on the Mariana Islands and anti-aircraft guns shot down about 37 Japanese aircraft during these raids. After the Marianas began to come under attack, the United States military stepped up its raids on the Japanese-held islands which could be used to launch raids on the B-29 bases. Particular attention was given to Iwo Jima, as it was correctly assumed that the Japanese aircraft which attacked the Marianas were flying from Japan and staging through the island en route to their targets. Following the first raid against Saipan in November, XXI Bomber Command B-29s were dispatched against Iwo Jima's airfields on November 5 and 8.
Japanese occupation of the Andaman Islands objective on the islands was the city of Port Blair. The garrison consisted of a 300-man Sikh militia with 23 British officers, augmented in January 1942 by a Gurkha detachment of 4/12th Frontier Force Regiment of the 16th Indian Infantry Brigade. Following the fall of Rangoon on March 8, however, the British recognized that Port Blair had become impossible to defend, and on March 10 the Gurkhas were withdrawn to the Arakan peninsula. The Japanese, seeking to secure their seaward flank, dispatched a force to seize the islands. The force was composed of the following units and ships: Distant Cover<br>