"Our positions near the village of Novo-Oleksandrivka, which is in the Luhansk sector, came under fire from rocket-propelled grenades and heavy machine guns. Since 05:50 [local time on Sunday], mercenaries of the Russian occupation force had been trying to oust our vanguard troops from their positions in the area of Svitlodarska Duha after long preparation fire from heavy artillery and mortars," the ATO HQ reported on Sunday.

The adversary forces, being in significant numbers, resorted to bypassing, attempting to cut off the ATO strongpoints.

"But their plans were uncovered on time. A battle, which followed, thwarted the invaders' plans. During the two-hour battle, our troops defeated the enemy fighters," it said.

"Unfortunately, we've had losses. Five soldiers were killed, six were wounded. Four of the soldiers were injured slightly and two had moderately severe injuries. All the injured have been provided with high-quality medical care," the ATO HQ said.

Reconnaissance reports said that the enemy's casualties were about 20 KIA's and up to 30 WIA's.

Read alsoUkraine reports 40 attacks on its positions in Donbas in past dayThe ATO HQ also updated on the situation in Donbas on Sunday, saying that from 00:00 to 18:00, Russia's hybrid military force continued shelling Ukrainian positions, mainly in the Mariupol and Donetsk sectors.

They used banned 122mm artillery systems to shell the village of Shyrokyne close to the Ukrainian-controlled strategic port city of Mariupol. Mortars of various calibers were used to attack the villages of Talakivka, Vodiane, Hnutove, and Shyrokyne. They also fired small arms on the village of Pavlopil. The town of Maryinka came under enemy sniper fire. What is more, a main battle tank was used to attack Shyrokyne.