Operation Otto was an Axis powers

Axis Powers

The Axis powers , also known as the Axis alliance, Axis nations, Axis countries, or just the Axis, was an alignment of great powers during the mid-20th century that fought World War II against the Allies. It began in 1936 with treaties of friendship between Germany and Italy and between Germany and...

 anti-partisan operation in Croatia

Croatia

Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

 in 1943. The objective was to destroy the Partisans operating out of the Grmeč Mountains in the Una-Sana bend area in West Bosnia southwest of the line Bosanski Novi - Prijedor

Prijedor

Prijedor is a city and municipality in the north-western part of Bosnia and Herzegovina. It is situated in the Bosanska Krajina region....

.

The Partisan force successfully managed to get through the enemy lines and passed out of the encirclement. There was little if any contact between the opposing sides and no losses were reported.