A smoke bomb (煙玉, kemuridama) creates a cloud of smoke when it detonates. It may look like small spheres wrapped in paper or like canisters. Smoke bombs are typically used to blind opponents and make them easier to attack. Alternatively, ninja can use smoke bombs on themselves so that opponents cannot see what they are doing. These bombs can contain different types of gaseous substances ranging from harmless ones used to simply create cover for a shinobi to advance or retreat, poison, and even sleeping gas, the latter of which was used by Sakura Haruno who learned to make the substance from Tsunade herself.
Smoke bombs are not restricted to smoke, and can instead be used to store sleeping or toxic gases for example.