Ukrainian troops appear to be conducting an operation on the Russian-held east bank of the Dnipro River in the southern region of Kherson.
Ukrainian forces are continuing their counteroffensive in the southern regions of Zaporizhzhia and Kherson.
US think tank the Institute for the Study of War on Tuesday quoted Russian military bloggers as saying that a Ukrainian amphibious transport vehicle has carried infantry fighting vehicles onto the east bank of Kherson. It suggests troops are mounting larger-than-usual ground operations there.
The think tank says the forces have likely conducted assaults across the Dnipro River since October.
Meanwhile, Russian drones and other weaponry appear to be targeting Ukraine's power sector.
Ukraine's Energy Ministry said on Wednesday Russia attacked Ukrainian energy infrastructure 60 times in the last several weeks.
Energy Minister German Galushchenko, visiting the United States, has held talks with senior State Department officials to discuss energy aid to Ukraine as winter approaches.
In yet another development, Russia's federal investigative committee, which handles serious crimes, said it has launched an investigation into the death of a Russian-appointed senior official in Russian-occupied Luhansk.
The proxy official died when his car exploded on Wednesday.
Ukraine's military intelligence claimed responsibility for the assassination on the same day, saying it was carried out with the cooperation of Ukrainian partisans in Luhansk.
The authority said on social media the proxy official had personally brutally tortured prisoners of war and civilian hostages.