"British 3-inch mortars supporting the 19th Indian Division's advance along the Mawchi Road, east of Toungoo in Burma, 1944." The Battle of Imphal-Kohima March - July 1944: British 3-inch mortar detachments support the 19th Indian Division's advance along the Mawchi Road, east of Toungoo, Burma. The mortar proved the most effective weapon in jungle warfare.