Lithuania's foreign minister said on Friday he had reports that 70 pieces of Russian military equipment had crossed the border into Ukraine during the night, Reuters reports.
"We are very much concerned about the situation developing (in Ukraine) because, on the one hand, we are talking very much about this so-called humanitarian convoy but, at the same time, we see that escalation continues, and we have reports that during the night 70 pieces of military equipment again entered through the border," Linas Linkevicius told reporters as he arrived for an emergency meeting of European Union foreign ministers.
A Russian aid convoy of around 280 trucks is parked near the Ukrainian border currently, media reports say. After inspecting the content, Ukraine officials agreed the aid could reach the rebel held city of Luhansk.
However, there's concerns after reporters and Ukrainian officials confirmed Russian military vehicles had entered Ukrainian territory on Thursday night.
Fears that the aid convoy was being used as a pretext for a Russian invasion of eastern Ukraine have been previously raised. Russia, however, says it's not arming the separatists and has called for peace in the region.