Warsaw and Kiev have condemned an apparent grenade attack on a Polish tourist bus in western Ukraine, days before Poland's president Andrzej Duda is due to visit the country to try to soothe strained relations.
The empty bus was charred and scarred by shrapnel in an explosion late on Saturday night near the city of Lviv. Ukrainian media quoted police sources on Monday as saying that an unidentified man had fired a rocket-propelled grenade at the vehicle before escaping in a car.
No one was hurt in the attack, which came as Mr Duda prepared to visit Ukraine on Wednesday and the two states try to halt a sharp deterioration in diplomatic ties due to disagreement over their bloody second World War history.
Poland’s foreign ministry confirmed “that a Polish bus was damaged by an explosive device, and notes with concern the latest anti-Polish incident on the territory of Ukraine”.
"I strongly condemn this provocation," said Ukrainian foreign minister Pavlo Klimkin, who has accused Russia of being behind previous such incidents.
"Someone is trying hard to put us at odds with Poland and disrupt the visit of president Duda. We will do everything to investigate this incident. And I say to the provocateurs – you won't succeed."
In March, the Polish consulate in the western Ukrainian city of Lutsk was also hit by a rocket-propelled grenade. No was injured in that incident, either.
War legacy dispute
Last month, Poland barred Kiev official Svyatoslav Sheremeta from the country and said it would no longer admit Ukrainians who allegedly play down wartime atrocities committed against Poles or glorify nationalist groups who fought for Ukraine's independence in the 1940s, sometimes alongside Nazi forces.
Warsaw has denounced Mr Sheremeta’s commission for halting the exhumation of the remains of Poles in western Ukraine, in response to anger in Kiev over vandalism and destruction of Ukrainian cemeteries and memorials in Poland.
Mr Duda said recently that he hoped Ukrainian president Petro Poroshenko would ensure that "people who openly express nationalistic and anti-Polish views will not hold important posts in Ukrainian politics".
Polish foreign minister Witold Waszczykowski last month accused Ukraine of "using" Warsaw for support in its conflict with Russia, while failing to address historical disputes.
Ukrainian officials accept that wartime pro-independence militia committed atrocities against Poles but reject Warsaw’s claim that they amount to genocide, and they want Poland to give official status to places on its territory where Ukrainian fighters were killed and buried.