The Japanese raiders, AIKOKU MARU and HOKOKU MARU, captured the British merchant ship GENOTA off Madagascar. Later in the month a seaplane from one of the raiders conducted a reconnaissance of the British base at Diego Suarez, in preparation for a midget submarine attack on the port. This attack was conducted on the same day, (in fact, taking into account time zone changes the attacks were only 70 minutes apart), as the midget submarine attack on Sydney Harbour on 30 May/1 June.