Russia claims that its forces have captured the front-line town of Kurakhove in eastern Ukraine’s Donetsk region.
The town has borne the brunt of Russian advances in recent months and is a stepping-stone to the key logistical hub of Pokrovsk.
Ukraine has not acknowledged the fall of Kurakhove, which is 35km (21 miles) south of Pokrovsk.
Fierce fighting has also been under way in Russia’s Kursk region in recent days after Ukraine launched a counter-attack on Sunday.
An image taken from social media and supplied by the Reuters news agency appears to show a soldier holding up a Russian flag in Kurakhove. The image has not been verified by the BBC.
Viktor Trehubov, spokesperson for Ukraine’s Khortytsia group of forces, told Reuters news agency that, as of Monday morning, Ukrainian forces were still engaging Russian troops inside Kurakhove.
Kurakhove is linked to Pokrovsk by roads that are part of the infrastructure to move troops and supplies along the front line.
The taking of Kurakhove would allow the Russians to go north to attack Pokrovsk from a new direction, analyst Roman Pohorily said.
Russia’s defence ministry also claimed on Monday that the village of Dachenske, which about 8km south of Pokrovsk, had been captured by its forces.
Kyiv’s forces are reportedly suffering from manpower shortages and have been losing ground in the east of Ukraine in recent months, as Russian troops advance.
