TOKYO—Japan’s National Police Agency said in a report Thursday that flaws in basic security such as an absence of metal detectors and bag checks allowed an attacker to enter a campaign crowd unnoticed and throw a pipe bomb at Prime Minister Fumio Kishida in April.
The bomb fell near Kishida and he was pushed away by special police before it exploded and he was unhurt.
A suspect, Ryuji Kimura, 24, was arrested at the scene of the April 15 attack in the fishing port of Saikazaki in the western prefecture of Wakayama, where Kishida was about to make a campaign speech for a local candidate….