It says 250 Ukrainian troops were killed with 16 tanks and 21 armoured personnel carriers destroyed. Moscow has consistently made exaggerated claims about the casualties its forces have inflicted. Videos posted online showed what were purported to be Ukrainian armoured cars blowing up in fields near Velyka Novosilka, 60 miles west of Donetsk city.

Ukraine’s daily update about the Russian invasion made no mention of a major offensive in Donetsk but did report 29 clashes in the Donetsk and Luhansk regions, and 15 airstrikes on enemy troops across the country. Ukrainian officials made no comment and emphasised the need for secrecy about operations in recent days as anticipation grows over counteroffensive.