MOSCOW: Russia on Wednesday said its forces had strengthened their position on the frontline near Avdiivka, a day after Ukraine warned Moscow was stepping up strikes to encircle the eastern town.

Avdiivka is symbolically and strategically important to Kyiv, lying just north of the Moscow-controlled city of Donetsk that was seized by separatist forces in 2014.

It has since become a symbol of Ukrainian resistance against Moscow, with Kyiv clinging on there despite relentless Russian attacks during the Kremlin's almost 20-month long offensive.

"Actions from the southern group of forces supported by aviation, artillery fire and heavy flamethrower systems, improved the situation along the front line in the vicinity of Avdiivka," the Russian defence ministry said.

Six killed in Russian shelling in eastern Ukraine

The Russia-installed head of the Donetsk region Denis Pushilin hailed some "progress toward the capture of positions."

"We see trends that the enemy has been retreating... but it is a bit early to say that there is a full-scale withdrawal of the enemy from Avdiivka," Pushilin told RIA Novosti.

Local Ukrainian officials on Tuesday told AFP that Moscow's forces had launched an artillery attack on the town in the morning and were firing incessantly.

"Battles continued throughout the night" in the north and south of the town, the head of the town's administration Vitaliy Barabash said Wednesday.

Barabash said Ukrainian troops were "most likely finishing" repelling Russian forces.

Ukrainian officials were "engaged in persuading people to evacuate every day", he said.

An 85-year-old man was killed by shelling in his courtyard, the Donetsk prosecutor's office said.

Ukraine's armed forces said Russian forces had "intensified actions" in several areas including Avdiivka.

"Our defenders repelled all enemy attacks and prevented the loss of lines and positions," military spokesman Andriy Kovalyov said.