Japanese police and experts are calling for regulations over so-called sling pistols, after an attack using the weapon occurred in the city of Osaka in April.
An investigative source said that sling pistols are so strong that projectiles shot at people's eyes can reach as far as their brains, while they can be acquired easily.
A sling pistol has a rubber bag attached to a handle. Users put ball projectiles in the bag, pulling them back and releasing them. They are more powerful and accurate than slingshots, which use rubber strips.