During the war, the Swiss Air Force engaged aircraft of both sides, shooting down 11 intruding Luftwaffe planes in May and June 1940, then forcing down other intruders after a change of policy following threats from Germany. Over 100 Allied bombers and their crews were interned during the war. Between 1940 and 1945, Switzerland was bombed by the Allies causing fatalities and property damage. Among the cities and towns bombed were Basel, Brusio, Chiasso, Cornol, Geneva, Koblenz, Niederweningen, Rafz, Renens, Samedan, Schaffhausen, Stein am Rhein, Tägerwilen, Thayngen, Vals, and Zürich. Allied forces explained the bombings, which violated the 96th Article of War, resulted from navigation errors, equipment failure, weather conditions, and errors made by bomber pilots. The Swiss expressed fear and concern that the bombings were intended to put pressure on Switzerland to end economic cooperation and neutrality with Nazi Germany. Court-martial proceedings took place in England and the U.S. Government paid 62,176,433.06 in Swiss francs for reparations of the bombings.