Illegal armed groups violated the ceasefire agreements 20 times from 1800 on Friday until 0600 on Saturday, the press center of the anti-terrorist operation (ATO) in Ukraine's east said in a report published on its Facebook account on Saturday morning.

"After midnight militants have already twice used weapons against our soldiers. Overall, 20 such cases have been registered since 1800 of yesterday," reads the report.

On Friday evening near Maryinka, militants shelled the ATO positions in the area of Sartana using small arms, and Shyrokyne using large-caliber machineguns.

North of Horlivka, militants used 82mm-caliber mortars to shell the Ukrainian military positions in the area of Zaitseve.

In Svitlodarsk, the unlawful armed groups were firing from grenade launchers and automatic weapons at Luhanske. Farther to the east, militants used heavy machine guns and small arms to fire on the ATO forces positions near Troitske.

The Ukrainian military positions also came under fire from small arms and grenade launchers in the area of Pisky, Opytne and south of Avdiyivka, the press center said.

All in all, on the first day of 2016 militants violated the cease-fire 42 times in the ATO zone, the press center said.