Ninja throwing stars have been around for many centuries, and are a trademark part of the traditional ninja arsenal of weapons. Known in Japanese as the hira shuriken or the shaken, the ninja throwing star is a flat, bladed throwing weapon with three or more striking points. The ninja throwing star was not designed to be a lethal weapon; rather, it was usually used to disable or distract an opponent. Shuriken, especially hira-shuriken, were often used by ninjas in novel ways—they might be embedded in the ground, injuring those who stepped on them (similar to a caltrop or makibishi), wrapped in fuse to be lit and thrown to cause fire, or wrapped in a cloth soaked in poison and lit to cover an area with a cloud of poisonous smoke. They can also be used as a handheld striking weapon in close combat. Ninja stars are extremely sharp and made of stainless steel or other very hard metallic material.