Sea War
Mediterranean: Germans use Neger (‘Negro’) human torpedoes against shipping off Anzio; 37 launched from beaches (24 lost) without result (night April 20-21). 6 Allied merchant ships hit by torpedo planes near Straits of Gibraltar.
Southeast Asia
Burma: Allied garrison on Summer House Hill, Kohima, relieved by British 2nd Division.
Air War
Britain: Abortive night raid on Hull.