 To simulate bullet hits on walls, grass, etc., instead of using  squibs, spots were marked for snipers to shoot on, even when actors  were near. This method (which is common practice in Thailand, where  this movie was shot) was used, because the setting up of squibs were  thought to be too time consuming. Actor Eddy Ko still has a scar on  his chest because one bullet ricocheted and hit him there.