Advancing 6 kilometres in a week is quite extraordinary under...

Advancing 6 kilometres in a week is quite extraordinary under the circumstances, considering the concentration of the Ukranian troops in the area.

Pokrovsk has been referred to as a "fortress" settlement, key to Ukrainian defenses preventing Russia's advance west of the Donetsk region.

Yuriy Butusov, a Ukrainian journalist and military observer, said on Wednesday that the situation for Ukrainian troops east of Pokrovsk was "critically difficult."

Russian forces advanced 6 kilometers, or just under 4 miles, toward Pokrovsk and the town of Myrnohrad—just east of Pokrovsk—in the past seven days, Butusov said. Once Russian forces enter Myrnohrad, they can fire directly onto Pokrovsk, he added.