Russian state media on Monday published and swiftly retracted reports of a withdrawal of forces from positions on the left (eastern) bank of the Dnipro River.
The reports quoted Russia's defence ministry announcing troops were being transferred "to more favourable positions" on the Russian-occupied left - or eastern - side.
The stories were quickly retracted.
The Russian defence ministry blamed the "false report" on Ukraine.
Ukraine claimed the announcement was a Russian disinformation operation being carried out against it.
Monday's hasty reversal took place almost exactly a year after Russian forces withdrew their troops from the right bank, including from the city of Kherson. The river largely continues to separate Ukrainian and Russian forces.
In the now-retracted reports, state news agencies Tass and RIA-Novosti said Russia had repositioned troops to positions east of the Dnipro river, in order to "free up some of its forces, which will be used for offensive operations in other areas".
They reflected similar language to those used in previous announcements of Russian retreats.
The Kremlin declined to comment on the incident, saying it was a matter for the military.
Ukrainian forces have escalated raids targeting Russian forces across the Dnipro in recent weeks - a key aim of its counter-offensive, which aims to slice through Russian occupied territory, severing a land corridor to the Crimean peninsula which Moscow annexed illegally in 2014.
On Friday, Russia claimed to have repelled a Ukrainian attempt to establish a beachhead - a landing position on a beach - which could have been used to bring heavy armour into the fight and would have represented a significant advance.
Still, the Institute for the Study of War (ISW), a US-based think tank, reported last week that Russian efforts to repel Ukrainian forces from the east bank had "not prevented Ukrainian forces from transferring additional personnel and materiel to positions on the east bank" of the river.
Separately, three civilians were killed by Russian attacks on Kherson on Monday, Ukrainian officials said.
And an earlier explosion which killed at least three Russian officers in the occupied city of Melitopol on Saturday was claimed by Ukrainian military intelligence. Kyiv said the blast was "an act of revenge" carried out by local resistance forces.
Ukrainian-linked fighters have claimed to have killed a number of Russian officials and local collaborators with car bombs and explosions. Last week, Mikhail Filiponenko, a former head of a separatist militia, was killed in the occupied city of Luhansk in an attack claimed by Ukraine.
