Explosive bomb*: The alchemist's bombs now have a splash radius of 10 feet rather than 5 feet. Creatures that take a direct hit from an explosive bomb catch fire, taking 1d6 points of fire damage each round until the fire is extinguished. Extinguishing the flames is a full-round action that requires a Reflex save. Rolling on the ground provides the target with a +2 to the save. Dousing the target with at least 2 gallons of water automatically extinguishes the flames.
Some things are worded strangely, but this one is not.