Ukrainian officials on Saturday shared photos appearing to indicate that Ukraine had retaken the northeastern railway hub of Kupiansk, potentially trapping thousands of Russian troops, Reuters reported.
"Kupiansk is Ukraine. Glory to the armed forces of Ukraine," Ukrainian regional official Natalia Popova wrote on Facebook.
This announcement comes as a Ukrainian counteroffensive continues to make gains near Kharkiv, according to NBC News. Kharkiv, located about 75 miles from Kupiansk, is Ukraine's second-largest city and has been under threat since the early days of the war.
"As of now, the armed forces liberated and took control of more than 30 settlements in the Kharkiv region," Ukrainian President Volodymyr Zelensky said Friday night.
The U.S.-based Institute for the Study of War estimated Saturday that Ukrainian forces had recaptured around 1,000 square miles of Russian-held territory. Based on "the influx of observed pictures of Russian prisoners of war," the ISW assessed that "Ukrainian forces are likely clearing pockets of disorganized Russian forces caught in the rapid Ukrainian advance."
Reuters suggested that the "collapse in Russia's frontline" is in danger of "turn[ing] into a rout."