Because of the breakthrough by the 11th Panzer Division towards Ostrog, Kirponos was concerned with German encirclement of the right flank of his Sixth Army. Therefore, at 2100 hours he ordered Lt. Gen. I. N. Muzychenko, commanding the Sixth Army, to begin pulling back to new defensive positions and anchored his right flank on Kremenets. At the same time, the XXXVII Rifle Corps was transferred under Muzychenko’s command. The Twelfth Army under Maj. Gen. P. G. Ponedelin was to pull back its right flank as well in order to maintain cohesive lines with the Sixth Army.
Colonel Bagramyan barely had time to send plans for disengaging the mechanized corps to Moscow for approval, when he received a prompt reply: “Immediately inform commander [Kirponos] that Stavka forbids the retreat and demands continuation of counteroffensive.” Kirponos rushed to the teletype room and contacted Stavka representatives in a futile attempt to get approval for his plans. He was refused and, dejectedly, instructed Bagramyan and Purkayev to inform the mechanized corps to continue the offensive on the 27th of June.
Summarizing the situation for day, Halder wrote:
Army Group South is advancing slowly, unfortunately with considerable losses. The enemy on this front has energetic leadership. He is continuously throwing new forces against the tank wedge, attacking frontally, as before, and now also the northern flank, and, on the railroad to Kovel, apparently also the northern flank. The latter attack will hardly develop to anything serious, but the southern flank at present is still vulnerable because we do not have sufficient forces available to give adequate infantry protection (the conveyor-belt system would be necessary here), and also because Armored Corps von Wietersheim (XIV Motorized Corps), which is still far in the rear, cannot get to the front at the moment because the bad roads are crowded with vital supply traffic. It will be the overriding task of OKH to maintain a steady flow of reinforcements behind Army Group South.[29]
JUNE 27, 1941
Morning of June 27 found the lines of the Soviet South-Western Front broken into two distinct fragments. The southern portion, composed of Sixth, Twelfth, and Twenty-Sixth armies, was firmly holding the Lvov salient and the Hungarian border. While the Sixth and Twenty-Sixth armies were heavily engaged, the situation along the front of the Twelfth Army was relatively calm, punctuated by minor skirmishes with Hungarian troops along the Carpathian Mountains. Of these three armies, the Sixth Army was the hardest-pressed, especially on its right flank, forcing it to hinge the right flank back and now face north.
The Soviet Fifth Army was now almost completely separated from the rest of the South-Western Front. The German spearhead, composed of the von Kleist’s Panzer Group 1, was forcing the flanks of Fifth and Sixth armies farther and farther apart. The schwerepunkt of the German attack now shifted towards Ostrog with only Task Force Lukin preventing a German breakthrough deep into operational maneuver space. In the area stretching from Rozhysche to Lutsk-Rovno highway, the shattered remains of the XXXVII Rifle and XXII Mechanized Corps and 1st Antitank Artillery Brigade were attempting to stem the German advance along the strategic highway.
The XV Rifle Corps with attached units, being the farthest forward, was preparing to begin falling back to come on line with the rest of the Fifth Army along the Goryn River. To bolster the chances of success of the mechanized corps’ attack, General Potapov detached the still-combat-capable 41st Tank Division, minus its motorized rifle regiment, away from the XV Rifle Corps and shifted it south to reinforce the IX and XIX Mechanized Corps.
Chief of staff of the 41st Tank Division, Col. K. A. Malygin, described condition of his unit in the following manner:
We had roughly 150 tanks, less than 100 dismounted tank crewmen, 24 howitzers; the motorized rifle regiment was left subordinated to the commander of the XV Rifle Corps. We did not have mortars or anti-tank cannon; our antiair defenses consisted of a lone air defense battery and four antiair machine gun systems. Obviously, it was extremely difficult to accomplish our mission in this situation. We could only temporarily halt enemy advance. German aviation bombed us nonstop until sunset. Even though casualties were minor, preparations for the counteroffensive were carried out in a difficult situation.[30]
Following Stavka’s instructions, Kirponos again ordered the VIII Mechanized Corps to attack Dubno from the south, the XV, Berestechko, and the IX and XIX were to operate against Mlynov and Dubno from the northeast and east. However, the IX and XIX Mechanized Corps were in no shape to advance, barely hanging on to Rovno under intense pressure from Germans divisions advancing along the Lutsk-Rovno highway.
General Kirponos became concerned that the Germans would turn their armored formations south, into the rear of Sixth and Twenty-Sixth Armies, in order to cut them off from the fortified districts along the old border. That was why he was deploying his reserve infantry corps and parts of three antitank brigades in the cutoff positions facing north. However, as I have already mentioned, the German command planned to carry out their southerly offensive later and further east—after breaching the old Soviet defensive line on the old border in the areas of Novograd-Volynskiy and Staroconstantinov.
IX Mechanized Corps, Maj. Gen. K. K. Rokossovskiy Commanding
While the XIX Mechanized Corps was falling back under intense German pressure, the IX Mechanized Corps made one last convulsive attempt to attack on Mlynuv. Its 35th Tank Division under Col. N. A. Novikov advanced to within ten miles north of Mlynov by 1300 hours. It was met by the German 299th Infantry Division and spent all day locked in combat with it. The 20th Tank Division under Col. M. E. Katukov, advancing on the left flank of the 35th Tank division, was engaged by German 299th and 13th Panzer Divisions. A spirited fight lasted most of the day. In the afternoon, the Germans discovered the unprotected flanks of the 20th Tank Division and gaps between its units and began to flank this division, threatening to take it from the rear and encircle it.
After holding on most of the day and buying the XIX Mechanized Corps as much breathing room as he could, Rokossovskiy ordered his corps to disengage and fall back. Attempting to preserve as many of his armored vehicles as possible, General Rokossovskiy’s corps pulled back to Rovno, bolstering beleaguered defenses of the city.
Isayev quoted Rokossovskiy’s reasoning: “I think, in this case it was more prudent to take personal responsibility and give the troops a mission that was based on existing situation before [we] received the directive from General Staff.”
XIX Mechanized Corps, Maj. Gen. N. V. Feklenko Commanding
Despite demands by the commander of the South-Western Front, the XIX Mechanized Corps was in absolutely no shape to conduct offensive actions on June 27. In fact, it was steadily being pushed east by elements from German 13th Panzer and 299th Infantry divisions. General Feklenko’s corps was being slowly squeezed into diminishing positions south and southeast of Rovno, desperately attempting to prevent or minimize German crossing of Goryn River.
After the Germans breached the defensive positions of the 228th Rifle Division approximately five miles south of Rovno, the Soviet forces defending the city were in real danger of finding themselves on the wrong side of the river. In late evening, one particularly fierce German probe reached the southern outskirts of the city before being beaten back by a tank counterattack. Shortly thereafter, and with heavy heart, I. I. Feklenko ordered his corps to pull back across the Goryn River, less than fifteen miles east of Rovno, exposing the southern approaches to the city.