Ukrainian forces launched a fresh attempt to break across the Russian border into the Belgorod region on Tuesday.
Russian military bloggers said that hundreds of Ukrainian troops supported by armoured fighting vehicles had mounted an attack on the Nekhoteyevka border checkpoint.
Other reports suggested a second thrust was made further east along the frontier at the Shebekino checkpoint.
The attempted cross-border raids came as Ukraine’s occupation of Russia’s Kursk region, which neighbours Belgorod, entered its fourth week.
Oleksandr Syrskyi, Kyiv’s top general, told a news conference that his forces had captured 500 square miles of Kursk, forcing Russia to deploy 30,000 troops to the area.
Ukrainian forces have launched several attempts to secure a breakthrough into the Belgorod region since the beginning of the ambitious Kursk offensive on Aug 6.
“There is information that Ukraine is attempting to break through the border of Belgorod Oblast,” Vyacheslav Gladkov, the governor of the region, wrote on the Telegram messaging app on Tuesday.
“According to the Russian defence ministry, the situation on the border remains difficult but under control.”