Ambassador Melinda Simmons / Photo from UNIAN

"[I] extremely concerned by reports of [a] sharp increase in ceasefire violations near [the] Zolote disengagement area with heavy weaponry proscribed under Minsk agreements, leading to casualties. Russia must use influence over its proxies to implement Minsk agreements fully," she said on Twitter on February 18.

Read alsoEU calls on Russia to make illegal armed formations in Donbas observe full ceasefire

As UNIAN reported earlier, Russian occupying forces on Tuesday morning attacked Ukrainian defense positions in Donbas, using 120mm mortars proscribed by the Minsk agreements. Under fire cover, the Russian invaders began their offensive operation and attempted to advance across the contact line.

One Ukrainian soldier was killed and another five were wounded amid the fight. The enemy's casualties included four killed and six wounded.