The invading German force was equipped with 2000 modern war planes, which were deployed on 1 September 1939 at dawn in Operation Wasserkante, thus opening the September Campaign against Poland; there was no declaration of war. The "Luftwaffe's" first sorties of the war targeted Polish cities with no military targets of any kind; for example, the city of Wieluń was destroyed almost completely by 70 tonnes of munitions dropped within several hours in spite of the fact that it had no strategic importance to the Germans, and the city of Warsaw was bombed as well.