This was the Croat and German part of the operation known to the partisan forces of Josip Broz Tito as the Second Enemy Offensive (14/23 January 1942) within the context of the two-part ‘Südost-Kroatien’, and intended to destroy the partisan forces in eastern Bosnia (27 January/6 February 1942).
After the failure of their ‘Ozren’ (i) offensive, the Croats decided to launch a second offensive, this time with German support, and the concentration of the necessary forces started on 24 January under the command of General Pješastva Djuro Iser. These forces comprised Generalleutnant Hans-Johann Fortner’s German 718th Division reinforced by the 697th Regiment of Generalmajor Albrecht Graf von Digeon von Monteton’s German 342nd Division, elements of Iser’s II Domobran Corps and General Pješastva Mihailo Lukić’s III Domobran Corps (primarily Pukovnik Artur Gustović’s 4th Division) and a number of Ustaše units including the ‘Franceticev’ Battalion. Supported by 60 pieces of artillery, three armoured trains and several engineer units, an Axis force totalling 17,000 men fought four battalions of the ‘Ozren’ Partisan Detachment with perhaps 1,200 men.
The operation started in difficult winter conditions characterised by very low temperatures and deep snow, for which neither side was adequately equipped or trained.
The Axis plan was for one of three groups to establish and hold a fortified position in the valleys of the Bosna and Spreča rivers near Doboj, and for two other groups to sweep forward from Tuzla and Zavidovica in an effort to compress the ‘Ozren’ Partisan Detachment into the triangle bounded by the rivers and lines of communications in front of Doboj, where the partisans would be destroyed.
The operation was commanded by Fortner, and the major role was assumed by Germans, leaving the Croats to occupy and secure the areas which the Germans cleared of partisans. In their first attacks the Germans made some progress, inflicting about 150 casualties on the partisans, but the latter then ceased their efforts to tackle the Germans in a conventional military fashion, which had availed them well against the poorly trained and poorly equipped Croats, and resorted instead to guerrilla tactics.
The Germans ended their effort on 6 February and fell back to Doboj. After this the ‘Ozren’ Partisan Detachment went over to the offensive against the Croats, inflicting more than 400 casualties on them.
Despite its success in the two ‘Ozren’ efforts, the ‘Ozren’ Partisan Detachment existed for only two more months: on 18 April 1942 a Četnik coup in this and other detachments in eastern Bosnia eliminated the communist leadership and forced the surviving communist into concealment.
On 28 May 1942, in Lipovac near Doboj, the Ozren Četnik detachment, led by Cvijetin Todic, Cvijetin Duric and Branko Stakic, reached an agreement with the Ustaše authorities recognising sovereignty of Croatia and swearing allegiance to this puppet state.