On 21 April, a gap had formed between the Polish infantry units (8th and 9th infantry divisions) and the 1st Armored Corps pushing towards Dresden, and the Polish units which were securing the Muskauer Forst region. The 7th and 10th infantry divisions were engaged near Neisse and the 5th Infantry Division and the 16th Tank Brigade were in transit in between those two groups. The Polish units were stretched over a line of . The Germans took the opportunity to push into this gap. The battle started on 21 April. In the west, the 20th Panzer Division started its drive on Bautzen, while in the east the 17th Infantry Division advanced on Niesky and Weißenberg, freeing trapped German troops on its way. The Germans drove between the Polish Second Army and the Soviet 52nd Army around Bautzen, some north-east of Dresden and west of Görlitz, sweeping the Soviet units of the 48th Rifle Corps, and driving towards Spremberg. Major General M. K. Puteiko, commander of the 52nd Army's 254th Rifle Division of the 73rd Rifle Corps was mortally wounded around Bautzen. At first, Polish general Świerczewski continued with his attempt to take Dresden, which contributed to the growing chaos in the Polish forces, as many communication lines were cut. The Germans succeeded in linking up with the remnants of their forces in the Muskauer Forst, and throwing the local Polish and Soviet forces into chaos. The Polish Second Army lost cohesion and split into four groups. Several units of the Polish Second Army found themselves surrounded. In particular, the Polish 5th Infantry Division and 16th Tank Brigade were struck in the rear, suffering severe losses. The headquarters of the 5th Division, defended only by sapper and training battalions, came under attack. The command group managed to break through to the 16th Tank Brigade, but that unit itself was almost annihilated at Förstgen (Forsiegen); out of 1,300 soldiers, only about 100 survived. The commanding general of the Polish 5th Infantry Division, Aleksander Waszkiewicz, was killed. In the village of Niederkaina, today a part of Bautzen, between 196 and 300 captured German members of the Volkssturm were locked in a barn which was set on fire by retreating Polish or Soviet troops. By 23 April the German breakthrough reached the Schwarzer Schöps River in the east, and Lohsa, Oppitz and Grossdubrau in the west. The main body of the German force was