Ukraine's military on Friday accused Russia of shelling its territory for the first time since the signing of a nominal ceasefire in early September.
"Over the past day, for the first time since the signing of the Minsk agreement, the shooting of Ukrainian territory restarted from the side of the Russian Federation," said Ukrainian military spokesman Andriy Lysenko.
Lysenko said that artillery was fired at a border post in Ukraine's war-ravaged Lugansk region from the direction of the village of Manotsky in Russia's Rostov region.
Kiev and the West accuse Moscow of pouring in troops and weapons to bolster the pro-Russian rebellion in the east that has cost the lives of some 4,300 people since April.
Lysenko said that Russian army units on Ukrainian territory and formations of separatist fighters were reinforcing their positions and that heavier shelling had been seen in the direction of the key government-held port city of Mariupol.
Moscow denies that it is involved in the fighting in the east although it does give the separatists open political backing.
Kiev and the rebels inked a Russian-backed truce deal on September 5 but the agreement did little to stop the fighting in the region and some 1,000 more people have been killed since then, according to the United Nations.
Before the ceasefire, Kiev frequently accused Moscow of launching shelling across the border.