Wehrmacht responded brutally to acts by alleged insurgents during the invasion of Poland in 1939 and was responsible for indiscriminate shootings of prisoners of war and civilians, among them Jews. Any act of defiance was met with the most ruthless violence, although the Army leadership did seek to discourage so-called "wild" shootings where Wehrmacht troops would shoot civilians on their own initiative or participate in murders conducted by the SS. Court-martial proceedings were begun against some of the junior officers who had led these shootings, but this was nullified on 4 October 1939, when Hitler pardoned all military personnel who had been involved in war crimes in Poland. After the end of hostilities, during the Wehrmacht's administration of Poland, which went on until 25 October 1939, 531 towns and villages were burned; the Wehrmacht carried out 714 mass executions, alongside many incidents of plunder, banditry and murder. Altogether, it is estimated that 16,376 Poles fell victim to these atrocities. Approximately 60% of these crimes were committed by the Wehrmacht. Wehrmacht soldiers frequently engaged in the massacre of Jews on their own, rather than just assisting in rounding them up for the SS.