Smoke grenade
A 'smoke bomb' or 'smoke grenade' is a bomb that produces a cloud of smoke. It can be used as a toy to make large clouds of colored smoke. It is normally used in the military though. Smoke bombs are used to hide positions and objects from sight behind a thick cloud of smoke. Armies also use smoke grenades to hide soldiers from the enemy. Smoke bombs can be thrown or shot. They normally contain a powdered chemical that is ignited. It produces a large cloud of smoke quickly. Then something else starts burning, keeping the smoke cloud thick.