Beyond this trivial complaint, the Army and the "Einsatzgruppen" worked closely and effectively. On 6 July 1941 "Einsatzkommando" 4b of "Einsatzgruppe" C reported that "Armed forces surprisingly welcome hostility against the Jews". Few complaints about the killings were ever raised by Wehrmacht officers. On 8 September, "Einsatzgruppe" D reported that relations with the German Army were "excellent". In the same month, Stahlecker of "Einsatzgruppe" A wrote that Army Group North had been exemplary in co-operating with the exterminations and that relations with the 4th Panzer Army, commanded by General Erich Hoepner, were "very close, almost cordial". In the south, the Romanian Army worked closely with "Einsatzgruppe" D to massacre Ukrainian Jews, killing around 26,000 Jews in the Odessa massacre. The German historian Peter Longerich thinks it probable that the Wehrmacht, along with the Organization of Ukrainian Nationalists (OUN), incited the Lviv pogroms, during which 8,500 to 9,000 Jews were killed by the native population and "Einsatzgruppe" C in July 1941. Moreover, most people on the home front in Germany had some idea of the massacres being committed by the "Einsatzgruppen". British historian Hugh Trevor-Roper noted that although Himmler had forbidden photographs of the killings, it was common for both the men of the "Einsatzgruppen" and for bystanders to take pictures to send to their loved ones, which he felt suggested widespread approval of the massacres.