Ukrainian forces claim to have attacked and destroyed a Russian military convoy that crossed the border into Ukraine during the evening on Friday. President Petro Poroshenko disclosed the event during a phone call with U.K. Prime Minister David Cameron, before announcing the news on his official website.

A statement from the Russian Foreign Ministry also confirmed that the strike had taken place, but they conveyed a more aggrieved tone and denied that anything was destroyed. They also deny that Russian vehicles even crossed the border into Ukraine, and say the incursion was on their side of the border. Ukrainian customs officials have gone across the border to inspect the convoy, but reports say the trucks are mostly empty.

The Ukrainian military officials say they tracked the movements of what's being described as a Russian armored column — one that appeared to be accompanying a fleet of trucks carrying humanitarian aid — and then destroyed part of it with its artillery when it crossed the border.

"Appropriate actions were undertaken and a part of it no longer exists," military spokesman Andriy Lysenko told journalists.

The New York Times said that it "was not clear whether Russian soldiers or rebel separatists were driving the vehicles." It added: 

In Copenhagen, the secretary-general of NATO, Anders Fogh Rasmussen, said that the alliance had detected an “incursion” of vehicles from Russia last night, adding: “What we have seen last night is the continuation of what we have seen for some time.”

So neither side is disputing that some sort of confrontation took place, but no one can agree where, how much damage was done, and what they were actually shooting at. Observers in Europe are obviously concerned about further escalation of the conflict, and whether Russia will use the incident as the excuse to cross the border again.