Censor.NET reports citing the ATO HQ press center on Facebook.
"The events of the morning of July 20, 2017 in Krasnohorivka area have become another sad page for the Ukrainian people. An enemy saboteur and recon group infiltrated into Ukraine's Armed Forces positions and hit cunningly the positions of a mechanized battalion.
"The illegal armed gangs launched the operation with massive shelling of Ukrainian positions from Minsk-banned 120 mm missiles and tank missiles. At least four tanks were conducting fire from different positions," the report reads.
The saboteur group comprised 10 to 15 militants, ATO HQ said.
"Having discovered the enemy group, Ukrainian fighters opened fire upon the adversary. During the first minutes of the skirmish two our fighters were fatally wounded. One our soldier fired and sent two militants to hell, presumably fighters of Oplot battalion.
"Given the suddenness of the enemy's attack and combat losses of the Ukrainian defenders, the unit commander, in order to save the lives of his comrades, decided to withdraw to an intermediate position. When moving, two more mercenaries were killed.
"Subsequently, reinforcement arrived for the Ukrainian soldiers and reliably consolidated their positions. Unfortunately, the soldiers lost one fighter. As it turned out later, this shell-shocked fighter was captured by the enemy saboteur group. The life of another soldier could not be saved, he was fatally wounded," the headquarters said.
"Under massive small arms fire by the Ukrainian soldiers, the adversary was forced to retreat covered up by tanks, mortars, and mobile Grad missiles. During this part of the skirmish, three Ukrainian fighters received wounds of various severity.
"At 6 a.m. the density of the enemy fire from tanks and mortars somewhat decreased. To evacuate the injured fighters, medical vehicles advanced, but the enemy continued the shelling. A 120 mm missile exploded near the evacuation group and injured four servicemen.
"At 8:30 a.m., it became known from intercepted communication that the enemy lost four fighters. Two more killed occupants were evacuated upon the enemy retreat. The rest of them fled the skirmish scene, having left numerous evidence (on pictures) of Russian presence in the Donbas," the report reads.
Photos by ATO press center/Facebook
No battle casualties in Ukrainian Army over past day despite upsurge in artillery, mortar strikes, - ATO HQ(0)