This was a German and Croat operation against the partisan forces of Josip Broz Tito in the area of Zupanja, Šamac and Vrpolje within German-occupied Yugoslavia (19/21 October 1943).
The objective was the destruction of the 16th Assault Division in the area between the Sava river and the railway line linking Vinkovci and Županja in south-eastern Slavonia.
The German contribution to the operation took the form of elements of Generalleutnant Josef Brauner von Haydringen’s 187th Reserve-Division, one company of the 6/Polizeiregiment ‘Kroatien’, 12th Panzerkompanie zbV with nine tanks, and 6th and 64th Panzerzüge, while the Croat contribution was elements of Pukovnik Zvonimir Stimaković’s Syrmian Brigade, part of 2/1st Recruit Regiment, and one Sava river gunboat. The Axis forces failed to make meaningful contact with the partisans and the operation was called off before the end of the third day. The losses on each side were insignificant.