'Wintergewitter' (iii) was a German counter-offensive against the communist forces of Marshal Josip Broz Tito in the Syrmia region within German-occupied Yugoslavia (17/21 January 1945).

During November and December 1944, after the successful conclusion of their 'Beogradska operacija', the Yugoslav forces continued had their advance through Syrmia with the ground support of Bulgarian divisions and the air support of Soviet warplanes. However, the depleted ranks of the Yugoslav formations had been over-hastily filled with raw recruits and committed to operations in which they suffered heavy casualties while making frontal attacks to secure a breakthrough of the Germans' prepared defensive positions between Opatovac and Bosut via Lovas, Tovarnik, Sid and Adasevac.

As a result the arrival of reinforcements, with Generalleutnant August Wittmann’s 117^th Jägerdivision replacing Generalmajor Hubert Lamey’s exhausted 118^th Jägerdivision, the Germans were finally able to halt the Yugoslavs along the line between Sotin and the Bosut forest via Berak, Orolik and Otok, and then to launch a counter-offensive. With the last of their own attacks defeated and no further advance possible, the Yugoslav forces had called a halt to their offensive and embarked on the process of rebuilding and re-forming their combat-exhausted forces with fresh and better-trained men.

Not expecting a German counter-offensive so soon, the Yugoslavs decided to re-equip with newly arrived Soviet weapons, and their line was further weakened by the withdrawal of the Bulgarian troops, who had revealed poor performance during assaults, and this left the I Proletarian Corps and its exhausted units responsible for the entire line.

The Germans made a preliminary attack on 3 January 1945 in the area of Otok and Bosut against the 21^st Division, which was forced back with heavy losses. This attack served to warn the Yugoslavs of what the Germans were likely to be planning, and they therefore began to fortify their positions. A period of 10 days was too short for the proper training of fresh recruits in anti-tank combat and co-ordination between the infantry, artillery and anti-tank branches, however..

After a pause of one week, in which it stabilised and shortened its front line, General Hellmuth Felmy’s XXXIV Corps launched its 'Wintergewitter' (iii) counter-offensive against the I Proletarian Corps with Generalleutnant Wolfgang Hauser’s 41^st Division (latterly the 41^st Festungsdivision), Generalleutnant August Wittmann’s 117^th Jägerdivision and SS-Brigadeführer und Generalmajor der Waffen-SS Otto Kumm’s (from 20 January SS-Brigadeführer und Generalmajor der Waffen-SS August Schmidhuber’s) 7^th SS Gebirgsdivision 'Prinz Eugen', taking the Yugoslav forces completely by surprise.

The Germans achieved an advance all the way back to Sid before being pushed back to the line of Tovarnik by a Yugoslav counterattack on 19 January. In the three days of fighting the Yugoslavs suffered 1,232 dead and missing, 154 taken prisoner, three 122-mm (4.8-in) guns, 15 heavy anti-tank guns, 10 medium anti-tank guns, five light anti-tank guns, nine heavy machine guns, 102 light machine guns, large quantities of small arms, 11 trucks and two munition dumps with more than 80 tons of ammunition.

Within the I Proletarian Corps, losses totalled 20% of its strength in the form of 243 dead, 648 wounded and 1,638 missing in two days of combat, while the 5^th Proletarian Division lost 434 dead, 727 wounded, 490 missing and 12 taken prisoner.