Poland and Ukraine held separate ceremonies on Sunday marking 75 years since a WWII-era ethnic conflict between their nations claimed thousands of lives, as a row over history continued to sour bilateral ties.
Discord over the Volhynia massacres between 1943 and 1945 has led to a diplomatic chill between Kiev and Warsaw, whose relations deteriorated after the nationalist Law and Justice (PiS) party came to power in Poland in 2015.
Polish President Andrzej Duda attended a mass commemorating the Polish victims of the conflict in Lutsk, a city in Ukraine's western Volhynia region.
Ukrainian leader Petro Poroshenko, meanwhile, was in the Polish village of Sahryn, 125 kilometres (80 miles) across the border, where he opened a memorial to Ukrainians killed by Polish partisans.
In 2016, Poland's rightwing-dominated parliament recognised the Volhynia massacres as a "genocide", a term that Kiev has rejected.
Between 1942 and 1945, members of the Ukrainian Insurgent Army (UPA) killed up to 100,000 Poles in the Volhynia region of what is now northwest Ukraine.
The UPA's main objective was to win Ukraine's independence by ousting Nazi and later Soviet occupiers and to clear Poles from territories that were historically Ukrainian land.
"It was ethnic cleansing, so that's what we would call it today," Duda said, quoted by the PAP Polish news agency at a cemetery in Olyka, near Lutsk.
The 2016 Polish resolution also recognises bloody reprisals by Polish partisan groups against Ukrainians that various sources say could have claimed up to 20,000 lives.
- 'Dialogue suspended' -
Duda also made reference to the reprisals by Polish partisan groups, but questioned the scale of the killing, insisting that there were around 5,000 victims.
Speaking in Sahryn, Ukraine's Poroshenko told members of Poland's Ukrainian community that "our nations deserve to know the truth, but it is not the job of politicians."
According to Piotr Tymon, head of the Union of Ukrainians in Poland, discussions about the massacres have come to an impasse under the PiS government.
"The discussion is focused only on one side; Polish victims of Volhynia. Dialogue about commemorating Ukrainian victims in Poland has been suspended," he told AFP by telephone before the ceremonies in Sahryn.
According to Tymon, who is also a historian, some 600 ethnic Ukrainian Polish citizens perished in the village that was one of several dozen in the region attacked by Polish partisans.
Despite these "terrible pages of history", Duda insisted that Poland "wants to support Ukraine in its reforms (for) the country to be a safe state."
Warsaw was one of the EU's strongest supporters of Ukraine's 2014 Maidan revolution that was followed by an ongoing conflict with Russian-backed rebels in the east of the country.
Both presidents said their visits were not official. Warsaw said Duda was invited to Ukraine by the local Catholic bishop in Lutsk. Kiev said Poroshenko was invited by Poland's Ukrainian community.
Several Ukrainian media reported Warsaw had refused an offer by Kiev to mark the anniversary together, citing anonymous diplomatic sources.
© 2018 AFP