A new cease-fire negotiated between Ukraine's government and Russia-backed separatists in the east held by a thread for a third day as both sides reported clashes near the strategic town of Debaltseve.
The two sides agreed to the so-called "indefinite" cease-fire last week, with the help of mediation from the Organization for Security and Cooperation in Europe (OSCE).
Ukrainian President Petro Poroshenko said the agreement reached on December 21 was a sign that his war-weary nation is on a road to lasting peace after nine previously negotiated cease-fires came unraveled.
Mortar and artillery fire has continued without any casualties.
"Our positions have come under attack 33 times since early Sunday," the Ukrainian military said in a statement.
Russian-backed separatists said their side had come under fire from Ukrainian grenade launchers 62 times in the past day.
The truce came after a battle for control of Debaltseve, which sits on a key rail link between the regions of Donetsk and Luhansk.
The two sides agreed to a similar holiday truce last year. It lasted for several weeks before fighting slowly resumed.
As of December 1, the UN's "conservative estimate" of the death toll among civilians and combatants since the conflict erupted in April 2014 is 9,758, with another 22,779 people injured.