'Lug' was a German and Croat operation against the partisan forces of Josip Broz Tito in the puppet state of Croatia in Axis-occupied Yugoslavia with the object of destroying a partisan concentration (5^th and 6^th 'Krajina' Brigades) in the Japra river valley to the north-west and west of Sanski Most in western Bosnia (2/7 November 1942).

The Axis forces included, as the German component, elements of the 721^st Grenadierregiment, 741^st Grenadierregiment, 661^st Artillerieabteilung and 714^th Nachrichtenkompanie of Generalleutnant Friedrich Stahl’s 714^th Division, together with the 1/202^nd Panzerregiment and, as the Croat component, the 3 and 4/3^rd Mountain Brigade, elements of the 1^st, 10^th and 11^th Regiments, 6^th Ustase Battalion, elements of the 4^th, 8^th and 18^th Ustase Battalions, Volksdeutsch Bataillon 'Ludwig von Baden', elements of the 1^st Assault Battalion, and 4^th, 5^th and 6^th Companies of the 'Banja Luka' Volunteer Battalion.

By forcing the partisans out of the Japra river valley, the Axis forces were able to restore the line of defence that protected the vital mining complex at Ljubija from the south-west. The partisans departed from the area, and there was little contact between the opposing forces.