443 rail transports on fire, damaged over 19,000 rail cars, and blew up 38 rail bridges, not to mention the attacks against the railroads. The Home Army was also responsible for 4,710 built-in flaws in parts for aircraft engines and 92,000 built-in flaws in artillery projectiles, among other examples of significant sabotage. In addition, over 25,000 acts of more minor sabotage were committed. It continued to fight against both the Germans and the Soviets; however, it did aid the Western Allies by collecting constant and detailed information on the German rail, wheeled, and horse transports. As for Stalin's proxies, their actions led to a great number of the Polish and Jewish hostages, mostly civilians, being murdered in reprisal by the Germans. The Gwardia Ludowa destroyed around 200 German trains during the war, and indiscriminately threw hand grenades into places frequented by Germans. The French Resistance ran an extremely effective sabotage campaign against the Germans during World War II. Receiving their sabotage orders through messages over the BBC radio or by aircraft, the French used both passive and active forms of sabotage. Passive forms included losing German shipments and allowing poor quality material to pass factory inspections. Many active sabotage attempts were against critical rail lines of transportation. German records count 1,429 instances of sabotage from French Resistance forces between January 1942 and February 1943. From January through March 1944, sabotage accounted for three times the number of locomotives damaged by Allied air power. See also Normandy landings for more information about sabotage on D-Day. During World War II, the Allies committed sabotage against the Peugeot truck factory. After repeated failures in Allied bombing attempts to hit the factory, a team of French Resistance fighters and Special Operations Executive (SOE) agents distracted the German guards with a game of soccer while part of their team entered the plant and destroyed machinery. In December 1944, the Germans ran a false flag sabotage infiltration, Operation Greif, which was commanded by Waffen-SS commando Otto Skorzeny during the Battle of the Bulge. German commandos, wearing US Army uniforms, carrying US Army weapons, and using US Army vehicles, penetrated US lines to spread panic and confusion among US troops and to blow up bridges, ammunition dumps, and fuel stores and to disrupt the lines of communication. Many of the commandos were captured by the Americans. Because they were wearing US uniforms, a number of the Germans