US Army (USA) Soldiers assigned to A Company, 2nd Battalion, 130th Regiment, Illinois Army National Guard (ILARNG) secure a residence and take Opposition Forces 4 (OP4) prisoner during a Military Operations on Urban Terrain (MOUT) exercise at the Novo Selo training area in Bulgaria. The simulated attack is part of Exercise BULWARK 2004. The Exercise is designed to train active duty, national guard, and reserve Soldiers in live-fire combat scenarios, convoy training and using the MOUT course. The Soldiers are armed with 5.56 mm M16A2 rifles equipped with Multiple Integrated Laser Engagement System (MILES) gear