To the south of the Waffen-SS, Vatutin took advantage of the lack of opposition in front of him to push his troops tirelessly forward. The Sixth Army, with two tank corps, two infantry corps and a cavalry corps, raced for the Dnieper crossing at Dnepropetrovsk, while Lieutenant-General M.M. Popov's Front Mobile Group of four tank corps pushed south, aiming for Krasnoarmeiskoye and the Sea of Azov.
Overestimating the capabilities of his SS troops, Hitler ordered them to attack southeast to close the gap with the First Panzer Army. Two groups were formed for the operation. A strong covering force was to remain around Kharkov under the command of Das Reich, which also included the Leibstandarte's 2nd Panzergrenadier Regiment and elements of the division's Tiger tank company, artillery and flak regiments. Hausser's corps headquarters and the Grossdeutschland Division also remained in the city, along with the 298th Infantry Division.
Kampfgruppe Peiper
The covering force fought an increasingly desperate defensive battle, and the frontline had to be pulled back to free troops for the coming operation to the south of the city. By 12 February, the Soviet VI Guards Cavalry Corps had punched a hole in the line separating the Leibstandarte from the 320th Infantry Division. Surrounded and burdened with thousands of wounded men, the army division needed help fast. A kampfgruppe was formed under SS-Sturmbannführer Joachim Peiper, then commander of the 2nd Panzergrenadier Regiment's armoured personnel carrier battalion, to rescue the division. He was given a column of ambulances and a detachment of StuG III assault guns for the mission. The kampfgruppe punched through the Russian front after destroying several tanks, and pushed 48km (30 miles) behind enemy lines to find the beleaguered infantry division. After loading up the ambulances, Peiper's men headed back to German lines, but a Soviet ski battalion had moved into place to block their path and destroy the main bridge over the River Udy, which the Waffen-SS column had to cross to return to Kharkov. The Waffen-SS kampfgruppe attacked and cleared out the Russians in house-to-house fighting, before repairing the bridge for the ambulances.