Operation "Trio" (1942-04-08)
- Published: 18 January 2011 18 January 2011
- Last Updated: 07 April 2012 07 April 2012
Dates: 8 April – 14 June 1942. (1)
Objective: Engage and destroy Partisan and Chetnik forces in East Bosnia.
Enemy Forces: 1st Proletarian Brigade, 2d Proletarian Brigade, 18 Partisan NOP Detachments and two independent Partisan battalions for a total of some 18,000 combatants.
Inf.Rgt. 737/717. Infanterie-Div.
1st Alpine Div. “Taurinense” (elements)
5th Mountain Div. “Pusteria” (elements)
22d Infantry Div. “Cacciatore di Alpi” (elements)
1st Alpine Group “Alpi Valle”
II Light Tank Group “San Marco”
XII Artillery Group 105/28
Several armored car squadrons
I Bn./13th Infantry Rgt.
8th Infantry Rgt. (2 companies)
15th Infantry Rgt. (2 companies)
IX Artillery Group (elements)
III and IV Military Frontier Battalions
Ustasha “Black Legion” (3 Ustasha battalions)
Conduct of Operations and Results: Originally planned as a large operation in East Bosnia that was to unfold in three phases beginning with “Trio I” on 15 April – a general clearing of the area south and east of Sarajevo, then “Trio II” – the clearing of the Drina bend, and finally “Trio III” – the destruction of insurgents in the Ozren Mountains. “Trio I” began before it was supposed to when the Ustasha “Black Legion” got into some heavy fighting with Bosnian Chetnik units on 8 April around Drinjača on the Drina. During the confusion of the next few days, most of the Communist Partisans in this area withdrew to the south toward the Italian zone of occupation, which necessitated a complete reappraisal of the operating plan. The Italians were unable to bring their forces into play by the date scheduled, so German General Bader, Komm.Gen. und Befehlshaber in Serbien (Commanding General and Commander in Serbia), requested authority to cancel the entire operation, which was subsequently approved. Meanwhile, German and Croatian forces from the Sarajevo area reinforced the Ustasha units pushing south from Drinjača and succeeded in clearing the Drina bend by 25 April. The Italian “Pusteria” Division simply acted as a blocking force on the southern periphery of the operation. This operation, together with Operation “Foča” which followed, was one of the most drawn-out to take place in Yugoslavia during the war, sputtered on in one form or another until 14 June 1942, with most of the fighting after 25 April taking place in Montenegro, Sandjak and Hercegovina between the Partisans and Italian forces (Operation “Foča”). In terms of casualties, the Germans lost 4 dead and 11 wounded, the Croatians 9 dead and 11 wounded, the Italians 3 dead and 1 wounded, while the Partisans lost 80 killed and 786 captured, according to German figures. These losses only cover those reported between 8 and approximately 25 April and do not include Italian and Partisan losses after that date during Operation “Foča”.
1. Aid, Matthew M. - The Croatian Armed Forced at War, 1941-1942, unpublished manuscript (Beloit (WI), 1976), pp.18-20; ; Hehn, Paul N. - The German struggle Against Yugoslav Guerrillas in World War II, East European Monograph No. LVII (New York: Columbia Univ. Press, 1979), pp.122-27; [Vojnoistorijski institute] - Oslobodilački rat naroda Juooslavije 1941-1945, 2 Vols (Belgrade: 1965), pp.207-12; Colić, Mladenko - Pregled Operacija na Jugoslovenskom Ratištu 1941-1945 (Belgrade: Vojnoistorijski Institut, 1988), pp.50-55; [Stato Maggiore Esercito - Ufficio Storico] - Le Operazioni delle Unita italiane in Jugoslavia 1941-1943 (Rome: Ministero della Difesa stato Maggiore dell' Esercito, 1978), pp.204; NARA WashDC: RG 242 (T-501 roll 250/361-69).