Donbas militants have shelled Ukrainian army positions and infrastructures of populated localities 360 times in the past four days, the anti-terrorist operation staff (ATO) spokesman, Anton Myronovych, has said.

"Most truce violations were observed when our country was celebrating Constitution Day," Myronovych said at a press briefing on Tuesday.

In his words, militants were mostly using mortars, including 120mm weapons outlawed by the Minsk agreements.

"Their increased use of tanks has been observed lately; they are shelling our positions and noncombatant cities," Myronovych said.

"The enemy keeps enlarging its gangs, rotating personnel and individual units and stealthily moving military hardware closer to the contact line. Populated areas near occupied Donetsk remain the epicenter of tensions," the ATO spokesman has said.

He reported the ongoing delivery of ammunition to militants from Russian territory. Meanwhile, Moscow has repeatedly declared the absence of Russian armaments in Donbas.

At the same time, according to Myronovych, the forces involved in the ATO in eastern Ukraine were almost done strengthening their combat readiness and capacities.

"There is no need to panic, ATO forces have practically completed their preparations and measures aimed at building up their combat readiness and capacity. We are in full control of the situation in every ATO sector. Units of the Ukrainian Armed Forces and other law enforcement agencies involved in the ATO are permanently prepared to act in any scenario," he said.

He said that Ukrainian weapons banned by Minsk agreements had been moved to the required distances from the contact line.

"The ATO forces are taking every necessary measure to build up their defenses," he said.