Russian forces, which control about a fifth of Ukraine since invading in February 2022, are advancing in eastern Ukraine in an attempt to take the whole of the Donbas, which is about half the size of the US state of Ohio.

Russia’s defence ministry said its forces had taken the town of Novohrodivka, which lies 12 km (seven miles) from Pokrovsk, an important rail and road hub for Ukrainian forces in the area. The town had a population of 14,000 before the war.

Yuri Podolyaka, an influential Ukrainian-born, pro-Russian military blogger, published maps showing Russian forces attacking beyond Novohrodivka in at least two places less than seven kilometres (fourmiles) from Pokrovsk.

Reuters was unable to immediately verify battlefield reports from either side due to restrictions on reporting in the war.

President Vladimir Putin said last week that a Ukrainian incursion into the Russian region of Kursk had failed to slow Russia’s own advance in eastern Ukraine and had weakened Kyiv’s defences along the front line in a boost to Moscow.

Ukraine’s top military commander said on Thursday that Kyiv’s incursion into the Kursk region was working and that there had been no Russian advances on Pokrovsk for the previous six days.

He said that one of the objectives of the Kursk incursion was to divert Russian forces from other areas, primarily Pokrovsk and Kurakhove. Russia had diverted large numbers to Kursk, but was also strengthening the Pokrovsk front, he added.

Ukrainian President Volodymyr Zelenskiy has said the Kursk operation was also to prevent Russian forces from crossing the border in the opposite direction.

Russia currently controls about 80 per cent of the Donbas. Given the speed of recent Russian advances in the east, some Russian war bloggers have raised concern about the army overreaching itself.

Putin ordered tens of thousands of troops into Ukraine in February 2022 in what he calls a special military operation. Ukraine and its Western backers have vowed to defeat Russian forces and expel all Russian troops.