Submarine "I-10"'s seaplane overflew Diego Suarez on May 29 after the Allied landings. As a result, submarines "I-16", "I-18", and "I-20" were ordered by Ishizaki to use their midget submarines to attack the ships in the harbour. HMS "Ramillies" and the tanker "British Loyalty" were damaged in the attack. "I-20"'s midget submarine crew of Lieutenant Saburo Akieda and Petty Officer Masami Takemoto were located and killed in a firefight with a Royal marines' patrol on the island near Anijabe; "I-18"'s did not participate in the attack due to a malfunction, and "I-16"'s midget sub never returned.