On the fateful day of July 11, 1943, UPA units surrounded and attacked Polish villages and settlements located in three counties - Kowel, Horochow and Wlodzimierz Wolynski. The events began at 3 in the morning, Poles had no chance to escape. The Ukrainians were using all kinds of weapons - axes, saws, knives, hammers. After massacres, all Polish villages were burned to the ground. According to those few who survived, the whole action had been carefully prepared, a few days before the massacres there had been several meetings in Ukrainian villages, during which UPA members were telling natives that slaughter of all Poles was necessary. In July, in the Polish village of Gurow, out of 480 inhabitants, 70 survived, in the settlement of Orzeszyn UPA killed 270 out of 340 Poles, in the village of Sadowa out of 600 Poles only 20 survived, in Zagaje out of 350 Poles only few survived. In September in the village Wola Ostrowiecka 529 persons died, including 220 kids under 14 and in Ostrowki - 438, including 246 kids. In September 1992 exhumation took place in these villages.
Norman Davies in "No Simple Victory" gives a short, but shocking description of the massacres. He writes: "The Jews of the region had already been killed by the Nazis. So in 1943-44 the wrath of the UPA fell on the helpless Poles (...) Villages were torched. Roman Catholic priests were axed or crucified. Churches were burned with all their parishioners. Isolated farms were attacked by gangs carrying pitchforks and kitchen knives. Throats were cut. Pregnant women were bayoneted. Children were cut in two. Men were ambushed in the field and led away. The perpetrators could not determine the province's future. But at least they could determine that it would be a future without Poles. They killed any number between 200,000 and half a million. Exact numbers of civilian victims remain unknown. Various historians estimate the number at between 35,000 and 60,000 in Volhyn alone.