 Complete the following phrase:  The remaining German troops and former naval personnel were reorganised as the regimental Kampfgruppe Skanderbeg under the command of SS-Obersturmbannführer Alfred Graf. The unit withdrew from the Kosovo region in mid-November along with the rest of the German troops in the area. Many Serbs and Montenegrins then took revenge against the regions ethnic Albanians, especially collaborators and those who had been members of the division. In his strongly apologetic history of the 7th SS Division, which he commanded at the time, Otto Kumm wrote that Kampfgruppe Skanderbeg reached Ljubovija on the Drina river, it was placed under the command of the 7th SS Division, which was securing the river crossings in that area. According to Kumm, the Kampfgruppe held the towns of Zvornik and Drinjača during the first half of December 1944 as part of the Ljubovija bridgehead. It withdrew across the Drina and fought its way north, towards Brčko on the Sava river, where it relieved the Wehrmacht forces holding the town. In late December, the Kampfgruppes assault gun battery was committed to the 