It was similar to a modern incendiary bomb, but its main purpose was to have explosive power to wound and kill enemies with broken fragments of its container, so the fire itself was not likely a very powerful attack.
現代でいう焼夷弾に似た兵器であるが、爆発力や容器の破片での殺傷が主目的で、炎での攻撃は威力が低かったと思われる。