
Ukrainian forces have entered the key eastern town of Kupiansk, as their rapid counter-attack makes further gains, officials say.
Kupiansk is a vital supply hub for Russian forces in eastern Ukraine and fell a week after February’s invasion.
Ukrainian special forces posted photos to social media which they said showed their officers in the town.
The advances would be the most significant since Russia withdrew from areas around Kyiv in April.
If confirmed – and held – the gains would be used as a sign that Ukraine’s army can take back Russian-occupied territory, while the country continues to ask for military support from the West.
For Russia, they would mark a humiliating setback, as its forces invaded the area in the early days of the war.
Earlier, UK defence officials said Ukraine had advanced 50km (31 miles) into previously Russian-held territory.
“Russian forces were likely taken by surprise,” the UK Ministry of Defence said. “The sector was only lightly held and Ukrainian units have captured or surrounded several towns.”
Ukraine launched its counter-offensive in the east earlier this week, while international attention was focused on an anticipated advance near the southern city of Kherson.