The Oskil River flows through Russia and Ukraine, down through the eastern part of the Ukrainian border region of Kharkiv. It has for some time constituted a front line in the area, where Ukrainian and Russian forces have entrenched themselves on either bank.
Ukrainian sources have in recent days sounded the alarm about a Russian attack where enemy forces attempted to cross the Oskil, about two miles from the border and just north of the larger Ukrainian city of Kupjansk.
"The enemy was crushed as a result of a successful operation. The right (western) bank of the Oskil is under the control of the defense forces," the Ukrainian military reports.
Russia's forces are advancing in the Kharkiv region, which they were pushed back from in the fall of 2022. They are once again moving towards the small town of Kupjansk, which was then under Russian occupation for several months.
Large numbers of households in the cities of Ternopil and Rivne in western Ukraine were left without power on Tuesday morning, after Russian drones struck facilities within the power grid.
"Stock up on water and charge your phones," wrote Ternopil's mayor Serhij Nadal on social media during the night.
Russia, on the other hand, claims further advances in southeastern Ukraine. The Russian military says it has taken control of two small communities, one in the Zaporizhzhia region and one in Donetsk.
Russia is estimated to have made the largest advances into Ukraine in November since March 2022.
