Glass Lanterns
From WikiRaider
There are several Glass Lanterns throughout Tomb Raider (2013). They can be shot with the Bow or any other weapon. If there are enemies standing under a lantern while Lara shoots it, said enemy will burn. This is quite an effective way to get rid of enemies that duck behind cover.
Glass lanterns can be hanging from the ceiling or standing on the ground. Some glass lanterns can be picked up and thrown to start a fire or an explosion, e.g in the Tomb of the Lost Adventurer Optional Tomb.
In the Pyromaniac Challenge Lara needs to shoot five glass lanterns. (For a list of locations see there.)