The Chitauri Bomb is one of the weapons used by the Chitauri troops that invaded Earth during the Battle of New York.
History
During the Battle of New York, some Chitauri forces managed to corner a large group of civilians, including Beth, inside a bank, and they intended to detonate one of these explosives to obliterate the hostages.
Captain America went to the bank to rescue the civilians, and while fighting the Chitauri soldiers, one of them launched the explosive at Rogers at short range in a kamikaze attack. Captain America was able to defend himself from the blast with his own shield, saving the civilians in the process.[1]