Japanese aircraft attacked Trincomalee, Ceylon according to the U.S. Joint Intelligence Committee. Daily summary dated 12 April 1942

An item reported that the Japanese attacked Trincomalee, Ceylon (Summary No. 122 dated 11 April 1942) with 54 bombers and 40 fighters. The British lost 11 planes. The Japanese however 7 during the attack 7 and during attacking their naval forces were another 18 destroyed, 12 probably destroyed and 2 damaged.  

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No.123 dated 12 April 1942.