In its short history, the SB committed acts of terror against civilians and non-civilians and their families, including people suspected either of collaborating, or serving with the Soviet forces in western Ukraine.
In this capacity, the SB also played a significant role in the ethnic cleansing and killing of the Polish population in Volhynia and Galicia.
On the orders of Dmytro Klyachkivsky, the UPA established "revolutionary tribunals" and military courts, which meted out death sentences for persons over the age of 17.
From its establishment the SB became a responsible authority for intelligence and counter-intelligence actions – however, numerous attempts to infiltrate agents into the Soviet partisan detachments has very limited success.
Issues of mixed families under resolving";[5] At same time actions against "internal threat" were not halted – all absorbed non OUN(B) military formation and especially their commanders has own "SB-Angels with hanging wire in hands."
After the war, in the years 1945–1948, Sluzhba Bezpeky conducted executions of Poles accused of collaboration with the communist government or actively opposing the Ukrainian resistance.
The Soviets took advantage of the situation by staging numerous provocations, the result of which was the death of many OUN members wrongly accused of cooperation with the communist security police.
"In village Diadkovichi SB unit murdered Sofia PAVLIUK, who heartily welcomed soldiers of the advancing Red Army."
"On the night of 19 September [1944] in the village Bolshaia-Osneshcha, Kolkovskyi raion, the STRESHA band, murdered four women, in whose apartments lived Red Army soldiers."
Typical Soviet counterinsurgency tactics in Ukraine were to arrest women suspected of belonging to UPA and imprisoning them, sometimes for months.
The large-scale use of such tactics provoked an atmosphere of mistrust and fear, leading to violent reprisals against women and others accused of being spies by UPA.
[13] On 21 June 1948 Soviet investigators uncovered eighteen corpses — seventeen female and one male that were allegedly killed since November 1947 by an OUN/UPA SB unit.
The SB squad allegedly responsible for the crime had nine members, and acted on the direct instructions of the commander of an UPA regiment based in a nearby forest.