Бій під Гурбами) – according to the Institute of History of the National Academy of Sciences of Ukraine, the largest battle that took place 21–25 April 1944 near the village of Gurby (Ukr.

The defeated German troops were no longer a threat to the UPA units, so the NKVD departments were the greatest danger to the Ukrainian insurgents.

Failing to meet significant resistance from the UPA troops, the Red Army continued its offensive against the German positions.

After the main forces of the Red Army passed through Western Ukraine, the UPA organised a number of military actions that were directed against NKVD troops, communists and civilians.

According to Petro Mirchuk, the main reason that led to the fighting at Gurby was an assassination attempt on the commander of the 1st Ukrainian Front, Nikolai Vatutin,[1] committed by a UPA detachment on 29 February 1944 near the village of Myliatyn.

Against the insurgents, the NKVD used 5 brigades of soldiers and some Red Army units, aviation, 15 light tanks, and a regiment of cavalry.

The next day, having broken through the defence line of commander Yasen, the NKVD troops surrounded and destroyed Storchan's camp.

On the night of 23–24 April 1944, UPA troops tried for the first time to break through the enemy's ring, but this attempt was unsuccessful and they were forced to take the battle in the Gurbenskie forests.

[5] It noted that a huge amount of ammunition, weapons, Soviet and German uniforms, food and barrels of petrol were captured.

[2][6] In the official report Beria, compiled for Stalin, Molotov and Chief of the General Staff of the Red Army Antonov indicated that in the fighting from 21 to 27 April losses of the NKVD were 11 killed and 46 wounded.

A description of the battle near Gurby was published in the newspaper of the Regional Cell of the OUN Provision "Na zminu" in July 1950.

Vasyl Kuk in his interview to Oleksandr Gogun stated that the UPA lost no more than 100 people, while the insurgents killed 1700 Soviet soldiers and wounded the same number of others.

[7] According to other data, the losses of Soviet troops totalled 120 people, Ukrainian insurgents – 80[8] plus Wehrmacht casualties, who support the nationalists.