with the regular units of the Soviet military. Instead, the UPA focused its energy on NKVD units and Soviet officials of all levels, from NKVD and military officers to the school teachers and postal workers attempting to establish Soviet administration. In March 1944, UPA insurgents mortally wounded front commander Army General Nikolai Vatutin, who liberated Kyiv when he led Soviet forces in the Second battle of Kiev . Several weeks later an NKVD battalion was annihilated by the UPA near Rivne. This resulted in a full-scale operation in the spring of 1944, initially involving 30,000 Soviet troops against the UPA in Volhynia. Estimates of casualties vary depending on the source. In a letter to the state defence committee of the USSR, Lavrentiy Beria stated that in spring 1944 clashes between Soviet forces and UPA resulted in 2,018 killed and 1,570 captured UPA fighters and only 11 Soviets killed and 46 wounded. Soviet archives show that a captured UPA member stated that he received reports about UPA losses of 200 fighters while the Soviet forces lost 2,000. The first significant sabotage operations against communications of the Soviet Army before their offensive against the Germans was conducted by the UPA in April–May 1944. Such actions were promptly stopped by the Soviet Army and NKVD troops, after which the OUN/UPA submitted an order to temporarily cease anti-Soviet activities and prepare for the further struggle against the Soviets. Despite heavy casualties on both sides during the initial clashes, the struggle was inconclusive. New large-scale actions of the UPA, especially in Ternopil Oblast, were launched in July–August 1944, when the Red Army advanced West. By the autumn of 1944, UPA forces enjoyed virtual freedom of movement over an area of 160,000 square kilometers in size and home to over 10 million people and had established a shadow government. In November 1944, Khrushchev launched the first of several large-scale Soviet assaults on the UPA throughout Western Ukraine, involving according to OUN/UPA estimates at least 20 NKVD combat divisions supported by artillery and armoured units. They blockaded villages and roads and set forests on fire. Soviet archival data states that on 9 October 1944, one NKVD Division, eight NKVD brigades, and an NKVD cavalry regiment with a total of 26,304 NKVD soldiers were stationed in Western Ukraine. In addition, two regiments with 1,500 and 1,200 persons, one battalion (517 persons) and three armoured trains with 100 additional