Japanese naval air base at Koepang, Dutch Timor attacked by Allied aircraft according to the U.S. Joint Intelligence Committee. Daily summary dated 21 April 1942

An item reported that Allied aircraft reconnoitered on 18 and 19 April Koepang, Dutch Timor, Dutch East Indies encountered by Japanese anti aircraft defence. The J.I.C. commented that in the past month Allied aircraft keep attacking Koepang forcing the Japanese as it seems of moving their naval air base to another position possible Ambon.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 132 dated 21 April 1942