A feature of the campaign in Russia was the activity of guerrilla bands which operated far behind the enemy lines and wrought havoc with his communications. These hardy warriors, some of whom are seen below, worked mainly at night, blowing up railway lines, mining roads and carrying out lightning attacks on isolated bodies of enemy troops. Their activities had a most demoralizing effect on the German soldiers who went in constant fear of swift and unexpected attack from these fierce and stealthy fighters.