Ukrainian forces have stepped up assaults across the Dnieper River near the southern city of Kherson, carrying out raids into Russian-controlled territory on the eastern bank. The increased activity has prompted speculation among analysts and in Russian military circles that Ukraine might be planning a more ambitious effort to open a new front in the war.

In recent days, Western military analysts have cited geolocated video footage that shows Ukrainian forces operating in a number of locations deeper behind enemy lines than previously witnessed.

"Ukrainian actions appear to be larger than previously observed tactical raids,” analysts at the Institute for the Study of War, a Washington-based research institute, said Thursday night.