KYIV (Reuters) -Ukraine said on Monday it had recaptured an eighth village during its counteroffensive in the Russian-occupied south but that the Kremlin's forces were trying to regain the initiative in the east by stepping up attacks.

Ukrainian soldiers held up yellow and blue national flags in a video circulated on social media in which they said they were inside Piatykhatky, a settlement on the way to one of the most heavily fortified Russian positions in the south.

"Today, June 18, the forces of 128 assault brigade chased out the Russians from the village of Piatykhatky. The Russians ran away leaving equipment and ammunition. Glory to Ukraine!" an unidentified soldier said.

Reuters confirmed the video had been filmed in Piatykhatky but was unable to verify the date.

A Russian-installed official in the partially occupied Zaporizhzhia region had said on Sunday that Kyiv's troops had retaken Piatykhatky, but that they had then been pushed out and that the settlement was now located in a "grey" area of control.

Deputy Defence Minister Hanna Maliar said Ukrainian forces had not only retaken Piatykhatky but had advanced by up to seven km (4.3 miles) into Russian lines in two weeks.

"In the course of two weeks of offensive operations in the Berdiansk and Melitopol directions, eight settlements were liberated," Maliar wrote on Telegram.

But in a later statement, she said the situation on the eastern front was "difficult".

"The enemy has pulled up its forces and is actively attacking in the Lyman and Kupiansk directions, trying to seize the initiative from us. High activity of enemy shelling is recorded. Hot fighting continues."

Maliar said that Russia had concentrated a significant number of units in the east, including air assault troops, but that Ukrainian forces were preventing their advance.

Reuters could not independently verify the battlefield claims.

(Reporting by Pavel Polityuk, Lidia Kelly and Anna Pruchnicka; Writing by Tom Balmforth; Editing by Timothy Heritage and Hugh Lawson)