 A great loss for the Partisans was the death of their capable and distinguished commander, Mladen Stojanović, known as "Komandant Mladen", who was killed in March 1942 by the Chetniks under Rade Radić.The German and Ustaše authorities realized that the city of Banja Luka and the iron mine in Ljubija were in danger and organized an offensive to destroy the movement.The Germans engaged 15,000 soldiers, the Independent State of Croatia about 21,000 soldiers, the Chetniks about 2,000 soldiers, and the Hungarians participated with 5 monitor ships.