Ukrainian artillery has destroyed part of a Russian armoured column that crossed overnight into Ukraine, according to the presidential website.
“Appropriate actions were undertaken and a part of it no longer exists,” RTE News reports military spokesman Andriy Lysenko as saying.
The news is also said to have been delivered to British prime minister David Cameron by Ukraine president Petro Poroschenko. The British government had since summoned the Russian ambassador to respond to the reports of the incursion under the cover of darkness.
Russia earlier accused Ukraine of attempting to disrupt a humanitarian aid mission to eastern Ukraine, after inspecting cargo contained in 280 trucks at a border point inside Russia.
Ukraine suspects the aid convoy could be a pretext for a Russian military invasion or further support for the pro-Russian rebels it has been fighting since April.
Reporters in the area say they have also seen armoured personnel carriers crossing the border with Ukraine, not far from the convoy of trucks claiming to carry aid supplies.
A column of 23 armoured personnel carriers supported by fuel trucks and other logistics vehicles with Russian military plates crossed through a gap in barbed wire fence into Ukrainian territory, according to the Guardian .
According to the Guardian “several military transporters loaded with artillery and tanks” had also been spotted following the humanitarian convoy, which was being escorted by two military helicopters.
Reports of renewed fighting in Ukraine knocked the stock market lower Friday. Major indexes headed higher at the start of trading, then sank following news that Ukrainian soldiers attacked a Russian military convoy.