A droid attack flare or an alert flare was an illuminated warning device used by the forces of the Galactic Republic during the Clone Wars. Firing a droid attack flare indicated that battle droids—of the Separatist Droid Army—had infiltrated or attacked Republic forces or territory. During the Clone Wars, the surviving clone troopers of a Separatist attack—Echo, Fives, and Hevy—fired a droid attack flare to warn the Clone Commander Cody and Clone Captain Rex of the Separatists' infiltration.