The hot spots were the towns of Avdiyivka and Popasna, and the village of Starohnativka.
Russia-led forces mounted five attacks on Ukrainian positions in Donbas, eastern Ukraine, on December 30.
No Ukrainian army casualties have been reported, according to the Joint Forces Operation (JFO) Headquarters' morning update on Facebook on December 31.
Read alsoDonbas war update: Ukraine records seven ceasefire violations on Dec 29
In particular, enemy troops used grenade launchers near the town of Avdiyivka, a large-caliber machine gun near the village of Starohnativka, while grenade launchers, large-caliber machine guns, and rifles were used near the town of Popasna.
The Joint Forces had to fire back, the JFO HQ said.
The violations were reported to OSCE representatives through the Joint Center for Control and Coordination (JCCC) of the ceasefire in Donbas.
A ceasefire was observed along other parts of the contact line.
From 00:00 to 07:00 on December 31, Russia-led forces mounted one attack on Ukrainian positions, using an anti-tank grenade launcher and rifles near Starohnativka.