evidence: Throughout Volhynia, individuals, often with their families, began to be killed, while in the Kostopol and Sarny counties in the northeastern part of Volhynia, where Ivan Lytvynchuk "Dubovy" was in command, the UPA proceeded to systematically murder Poles.[89] They attacked dozens of villages, the largest massacre of which took place in Lipniki, where one of the first Polish self-defences was established, but despite resistance during the attack on the night of 26–27 March, the "Dubovy" unit murdered 184 people.[89] About 130 people were murdered in Brzezina on 8 April 1943.[90] Then the massacres began to be carried out in the westward located counties, mainly in the Lutsk county.[91] According to Timothy Snyder, in late March and early April 1943, the UPA forces killed 7,000 Polish civilians.[92] [...] According to Ukrainian sources, in October 1943 the Volhynian delegation of the Polish government estimated the number of Polish casualties in Sarny, Kostopol, Równe and Zdołbunów counties to exceed 15,000.[165] Timothy Snyder estimates that in July 1943, the UPA actions resulted in the deaths of at least 40,000 Polish civilians in Volhynia (in March 1944, another 10,000 were killed in Galicia),[166] causing additional 200,000 Poles to flee west before September 1944 and 800,000 afterward.[51][166] [...] The historian Timothy Snyder considers it likely that the UPA killed as many Ukrainians as it killed Poles, because local Ukrainians who did not adhere to its form of nationalism were considered traitors.[9]