Heeresgruppe E
The Yugoslav 13th Corps, in cooperation with the Bulgarian 2nd Army, advanced from the south-east. They were responsible for the area of Niš and Leskovac. They were also responsible for cutting off the main evacuation route of Army Group E along the South Morava and Morava Rivers. Army Group E was forced to retreat through the mountains of Montenegro and Bosnia and was unable to re-enforce German units in Hungary.