This was announced at a briefing by NSDC Information Center speaker Andrii Lysenko, Censor.NET reports with reference to LigaBіznesІnform.
"This provocation by Russia was recorded by Ukrainian border guards near the village of Ilienko. After checking the border area the patrols revealed mortar positions and items of military ammunition," Lysenko said.
"Crossing the border by air helicopters has been spotted, but the guards took a pause and gave them an opportunity to turn around and go back. There will be a separate statement of the Council on this matter and we will keep track of Russia's responses," he said.