Among those killed were Maciej Rataj, Stefan Bryła, Tadeusz Tański, Mieczysław Niedziałkowski, Janusz Kusociński and Stefan Kopec. Actions were started on a similar scale in other Polish areas annexed by Nazi Germany. According to many historians, including Norman Davies, the action against Polish leaders was coordinated with the authorities of the Soviet Union, who at the same time perpetrated the mass murder of 22,000 Polish military officers at Katyń and other places.