Japanese navy blockading Hong Kong according to the U.S. Joint Intelligence Committee. Daily summary dated 23 December 1941

An item referred to the British Intelligence Singapore reporting that Hong Kong was blockaded by 2 Kuma-class cruisers, 2 destroyers and 2 motor torpedo boats.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 13 dated 23 December 1941.