"Extremely fierce battles" are raging in parts of Ukraine as Kyiv's forces continue their counter-offensive, the country's deputy defence minister says.
Ednews reports that Hanna Maliar wrote on Telegram that Ukrainian forces had managed to advance near Bakhmut in the east and Zaporizhzhia in the south.
But she conceded Russian forces were mounting a stiff defence in some areas.
Her comments come after another night of Russian missile and drones strikes on cities across Ukraine.
Russia has stepped up its bombing campaign in recent weeks, despite President Vladimir Putin admitting that his forces are suffering from a shortage of missiles and drones. The latest wave included a relatively rare strike on the Black Sea port city of Odesa.
Kyiv's much-anticipated advance has been long in the making, and Ukrainian officials have accused Russia of increasing strikes in recent weeks to deflect attention from the offensive.
The Ukrainians say their troops have recaptured seven settlements and at least 90 sq km (35 sq miles) since starting their counter-offensive.
Ms Maliar wrote on Telegram that Ukrainian troops had advanced around the city of Bakhmut, long the centre of a grinding and bloody street-by-street battle with Russian forces.
She said soldiers advanced by 200m to 500m towards the city, as well as advancing 300m to 500m in the southern Zaporizhzhia province. The BBC cannot independently verify these claims.
But she conceded that the counter-offensive had already led to some "extremely fierce battles", as Ukrainian forces try to break through well established Russian defensive lines.
Senior Western officials have warned against the idea that Russian forces will simply "melt away" in the face of Ukrainian attacks, adding that Kyiv's gains had already been "costly".
"Russian forces have generally put up a good defence from their well-prepared, defended positions and had been falling back between tactical lines," the sources said.
"This 'manoeuvre defence approach' is proving challenging for the Ukrainians and also costly to attacking forces. Hence, the advance at the moment has been slow," they observed, adding that it was too soon to say how effective Ukraine's offensive has been.
