For example in 1930 terror campaign and civil unrest in the Galician countryside resulted in Polish police exacting a policy of collective responsibility on local Ukrainians in an effort to "pacify" the region.

[10] Beginning in 1937, the Polish government in Volhynia initiated an active campaign to use religion as a tool for Polonization and to convert the Orthodox population to Roman Catholicism.

[citation needed] The communists organized strikes, killed at least 31 suspected police informers in 1935–1936, and assassinated local Ukrainian officials for "collaboration" with the Polish government.

[24] Particularly bloody were the actions of the Hryhoriy Goliash [uk] "Bey" unit in Brzeżany and Podhajce counties, which carried out massacres of a number of villages: Koniuchy, Potutorów, Sławentyn, Jakubowce and others, claiming lives of couple hundreds Poles.

[25] Where the Polish army could, it fought the militia, often taking brutal revenge, burning villages from which shots were fired and killing people caught with weapons.

[29] The roots of these events can be traced back to the ethnic cleansing of Zamojszczyzna (November 1942 – March 1943[30]), when the Germans, having expelled both Poles and Ukrainians, settled the latter in the Polish villages of the Hrubieszów district (during so-called Ukraineraktion [pl] in January–March 1943[31]).

[32] Andrzej Leon Sowa described the settlement of Ukrainians in these villages as an "effective German provocation" aimed at escalating ethnic conflicts in their occupied territories.

The Ukrainian Insurgent Army, formed in 1942 and fighting Polish and Soviet partisans, set about exterminating Poles and forcing them through terror to leave the disputed lands.

[41] The failure of the talks was determined by an increased influx of refugees to the Lublin region, survivors of the Volhynian tragedy, bringing news of the Ukrainian Insurgent Army's crimes in the area.

There are testimonies according to which the attack on Grabowiec was combined with the murder of an unspecified number of civilian Ukrainians,[46] one of the victims was the Orthodox priest Pavel Shvayko and his wife Joanna.

[50] on 24 December of the same year two platoons of the BCh Stanisław Basaj "Rysia" unit came to the aid of the Polish population once again attacked by the UPA (Ukrainian Insurgent Army) militia in Kol.

[55][56] The self-defense fought victorious battles with UPA units near: Przebraże ,[57] Pańska Dolina, Huta Stara,[58][59] Kuty, Rybcza, and Antonówka Szepelska.

[65] In addition to operations against the Germans, the division carried out 16 major combat actions against UPA units, partially removing the threat to the Polish civilian population in the west of Volhynia.

Throughout the month, Ukrainian partisan units and police officers carried out attacks on Poles, with several people falling victim to each (villages of Medycze, Terebiniec, Pielaki, Turka).

2 rifles, 3 grenades and nagans were captured [77] In the evening of 7 March 1944, in the forest Lipowiec near Tyszowiec, a concentration of the Tomaszów AK troops took place, in the strength of about 1200 soldiers, under the command of Lieutenant Zenon Jachymek "Wiktor".

The Poles captured and burnt the colonies of Alojzów, Brzeziny, Bereźnia, Dęby, Sahryń-Kolonia and the villages of Malice, Metelin, Strzyżowiec, Turkowice, Wronowice, Mircze, Prehoryłe, Terebiń, Terebiniec and Wereszyn.

[92] In response, the 8th company of the Telatyn AK under the command of "Szarfa" attacked Rzeplin, combining the elimination of Ukrainians considered particularly dangerous with the evacuation of Polish villagers.

During the evacuation of the Polish population, a massacre took place in Poturzyn - in the early hours of the morning a unit of the 14th SS Grenadier Division, supported by a subunit of the Ukrainian Insurgent Army (UPA), invaded the village, where a large group of refugees were located; 162 civilians were killed.

[99] In view of the unfavourable situation of the Polish units, the commander of the Tomaszów district of the AK suggested mobilising all the forces of the inspectorate for a new operation against the Ukrainian Insurgent Army and the UNS.

[102] On the night of 4–5 May 1944, Ukrainian Insurgent Army units made an unsuccessful attempt to capture the village of Nabróż, the easternmost Polish resistance point beyond the Huczwa River.

[103] Two days later, on 7 May, an UPA unit, at the request of Ukrainian peasants, undertook an operation to clear the colonies of Marysin, Borsuk and Andrzejówka, which had been a base for the Polish militia.

Also taking part in the fighting in the Nabruza area was the "Ostrizhsky" sotnia, which, as we read in the Ukrainian document, contributed significantly to the successful conduct of the entire operation.

The Ukrainian attack on 18–19 May led to the collapse of Polish defences in the eastern part of the Tomaszów and Hrubieszów districts of the Home Army, followed by the withdrawal of troops behind the Huczwa River for fear of encirclement.

[106] Such actions, however, had no effect, but as a result of them, contributed to the antagonism of the population of these regions, and finally, after many weeks of harassment, 21 may, a large UPA force of about 500 to 1000 attacked Narol, the base of the defenders contributed to the collapse of the UPA attack and the subsequent counter-attack, which caused the Ukrainians to rush and flee, 30 to 80 Ukrainians died in the battle, and many were wounded, Polish losses included 13 killed and 25 wounded.

On the eve of the battle, the units of the first grouping left the Tyszowiecki forest and advanced through Turkowice towards the village of Dąbrowa, which, however, could not be conquered as it was occupied by a strong Wehrmacht detachment.

Soon, in the greatest haste, units and groups of soldiers from neighbouring villages, including Pukarzów, Wólka Pukarzowska, Muratyń and Czartowiec, began to arrive and joined the fight spontaneously.

The Ukrainians recognized Maj. Stanisław Basaj, alias "Ryś", the commander of the Peasant Battalions during World War II, who was found and detained in one of the houses in Kryłów.

[123][125] Jan Pisuliński writes that as a result of the Polish-Ukrainian conflict in 1945 in the Przemyśl and Dobromil regions 1,000 Ukrainians were killed by the National Armed Forces and the Home Army, while Polish losses are unknown.

[150] The main perpetrator of massacres of the Poles in the Volhynia was the Ukrainian Colonel of the UPA Dmytro Klyachkivsky who was killed by the NKVD in the village of Orzhiv in the Rivne Oblast in 12 February 1945.

[151] While the Ukrainian commander-in-chief of the UPA Roman Shukhevych was one of the perpetrators of massacres of the Poles in the East Galicia committed suicide when the Soviet armed units numbered approximately 700 soldiers besieged his house in the village of Bilohorscha of the Lviv Oblast in 5 March 1950.