 Russia is concentrating more than 100,000 personnel, more than 900 tanks, for new offensive. Russian sabotage units tried unsuccessfully to cross the Ukrainian border into Sumy and Chernihiv Oblasts. Lieutenant-General Serhii Naev of the Ukrainian Army said, The Russian Federation does not cease trying to find weak points in our defence in the Chernihiv and Sumy directions. The general wrote on Telegram, a penetration of sabotage groups at the border was recorded, but all attempts were unsuccessful. Naev said that the military is working together with local administrations to strengthen the security of the border regions by installing barriers and cameras. In the case of an increased threat, the military will provide sufficient reinforcements to prevent the Russian forces from crossing into Ukraine's territory in these areas, the general added. The Sumy and Chernihiv Oblasts lie at Ukraine's northern border with Russia. Both of them were invaded and partially occupied during Russia's initial onslaught in February 2022, but the invading forces withdrew in April after the Kremlin's failure to take Kyiv. Meanwhile, Russia is attempting to gain ground in the Kupiansk area, Kharkiv Oblast, and continues the offensive into the depth of our battle formations. Colonel-General Oleksandr Syrsky, commander of Ukraine's ground forces, said, Russia is concentrating more than 100,000 personnel, more than 900 tanks, more than 555 artillery systems, 370 MLRs in the Lyman-Kupiansk direction, according to Serhi Cherovati, spokesperson for Ukraine's eastern military command.