Sloviansk, the anchor of Ukraine's Donbas fortress belt, has been designated an active combat zone by its own regional authorities.

The Donetsk Regional Military Administration made the designation on August 21, according to the Sloviansk has become a combat zone war report published on August 25 by Warsaw's Centre for Eastern Studies, or OSW.

It followed a heavy bombardment of Sloviansk and neighbouring Kramatorsk the day before, which killed one person and injured 24, and Russian troops pushing into the town of Mykolaivka, where the Sloviansk thermal power station sits idle.

The declaration is important after Kostiantynivka fell to the Armed Forces of Russia (AFR) earlier this month – the first of the three so-called Donbas Fortress cites to be captured by Russia. Sloviansk and Kramatorsk are the other two cities.

The change of status for Sloviansk triggers a mandatory evacuation planning (including monetary compensation for residents), for the withdrawal of civil services and for the emergency legal regime that has preceded the loss of every large Ukrainian town since Bakhmut. Kyiv has spent two and a half years insisting the fortress belt would hold, but the defences of the strategic important cities appear to be crumbling.

The shape of the attack

Russian forces have made further gains on a broad front east of both cities but cannot yet close the pocket from the north, where Ukrainian counterattacks around Lyman are working, OSW said.

Four lines of pressure have taken shape: from the east towards Sloviansk and Kramatorsk, from the south-east and south-west towards Druzhkivka, from the south and east towards Dobropillia, and from the north and east through Lyman. Russian sabotage and reconnaissance groups have entered Dobropillia itself.

Increased volumes of drone around these towns have moved the frontline. FPV drones attacking Dobropillia and its surroundings have reached 1,200 a day, and those hitting Druzhkivka and its supply routes 1,500 to 2,000 a day, according to Ukrainian sources cited in the report. At that density the roads into a defended town stop working before the town does.

In Zaporizhzhia region the fighting is around Orikhiv, where Ukrainian counterattacks have pushed Russian infiltrators back out of the eastern districts, though the Russians have advanced to the north-east and, by some accounts, crossed the Verkhnia Tersa river.