Warsaw, Jul 7 (AP) Poland's prime minister and Catholic church leaders opened days of observances Friday to honour victims of World War II massacres of tens of thousands of Poles by Ukrainian nationalists, which have marred the tightening strategic relations between the neighbouring nations.

“We can say that for many years this has been an unhealed wound in Polish-Ukrainian relations," said spokesperson for Poland's ruling right-wing party, Rafal Bochenek.

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“We would expect truth to be told and things to be called by their proper name," Bochenek said.

Poland says the 1943-44 massacre of some 100,000 Poles by Ukrainian nationalists was genocide. The killings took place in Volhynia and in other regions of what was then eastern Poland under Nazi German and then Soviet occupation, and which are now in western Ukraine.

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Warsaw is among the staunchest supporters of Kyiv in its war against Russia's aggression and the increasingly close ties seem to provide an opportunity for the two nations to deal with the hurtful and divisive past.

Many Poles still harbour grudges for family members who were brutally killed in the massacres. In retaliation, some 15,000 Ukrainians lost their lives then.

Poland's Prime Minister Mateusz Morawiecki travelled early Friday to Ukraine to massacre sites, where the entire villages of Ostrowki and Puzniki had been wiped out by units of Ukraine's nationalist forces. He put up commemorative crosses there and visited local cemeteries where some of the victims were buried. Not all burial sites are known.

“I will not rest until the last victim of that terrible Volhynia Massacre is found and buried with respect," Morawiecki said.

Leader of Poland's Roman Catholic Church Archbishop Stanislaw Gadecki and the Major Archbishop Sviatoslav Shevchuk of the Ukrainian Greek Catholic Church held joint reconciliation religious service Friday in Warsaw.

These were the first in days of observances that will culminate on Tuesday, marking the 80th anniversary of the intensified violence.

Entire villages were burned down and all their inhabitants killed by nationalists and their helpers who sought to establish an independent Ukraine state.

Poland has long pursued Kyiv's permission for the search for burial sites, exhumations, identification and commemoration of the Polish victims.

Some of the Ukrainian nationalist leaders who were responsible for instigating the massacres are lauded in Ukraine for fighting for the nation's independence during World War II, leading to strains in relations with Poland. But Ukraine's authorities recently signalled a more open approach to Poland's expectations.

Poland's leaders have insisted that bringing the full truth into the open will strengthen bilateral relations with Ukraine and neutralise vulnerabilities that could be exploited by third countries seeking to undermine these ties.

“We must be aware, Poles and Ukrainians, that without the full clarification and full record of the Volhynia crimes, Russia will always be using this card to drive a wedge between Poles and Ukrainians," Morawiecki said. (AP)

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