Other tactics include directing artillery or mortar fire onto suspected sniper positions, the use of smoke screens, placing tripwire-operated munitions, mines, or other booby-traps near suspected sniper positions. Even dummy trip-wires can be placed to hamper sniper movement. If anti-personnel mines are unavailable, it is possible to improvise booby-traps by connecting trip-wires to hand grenades, smoke grenades or flares. Though these may not kill a sniper, they will reveal their location. Booby-trap devices can be placed near likely sniper hides, or along the probable routes to and from positions. Knowledge of sniper field-craft will assist in this task.