(AFP) - Large numbers of Russian forces are storming the frontline Ukrainian town of Avdiivka, its Ukrainian mayor said Thursday, escalating a months-long effort to capture the industrial hub.

Moscow launched a costly bid in October to seize the town, which has been caught up in fighting since 2014, when it briefly fell to Moscow-backed separatists.

"Unfortunately, the enemy is pressing from all directions. There is not a single part of our city that is more or less calm," mayor Vitaly Barabash told state media.

"They are storming with very large forces," he added.

The capture of Avdiivka would provide a much needed victory for Russia, in the run-up to the second anniversary of its fully-fledged invasion and its March presidential election.

It would also mark the first significant change along the frontline in months, despite fierce and costly fighting that has stretched the resources of both sides.

Yet analysts suggest that the town, which lies in a Ukrainian-controlled pocket, holds little strategic value for either military.

Barabash said that Russian forces were mainly employing artillery, airstrikes, and infantry in the assault, because Russian tanks and armoured vehicles could not pass on the soft ground.

He characterised the fighting as "very hot" and "very difficult".

"The situation in some directions is simply unreal," he said.

Fewer than 950 residents remain of an estimated pre-war population of around 33,000 people, he added.

- Drone barrage -

Avdiivka is located in Ukraine's eastern Donetsk region, which the Kremlin claims is part of Russia, along with four other Ukrainian territories that Moscow says it has annexed.

President Vladimir Putin last month was the first Russian official to claim that his forces had gained a foothold in the city.

Further east in Donetsk region, emergency services said Thursday that one person had been killed and seven more injured during Russian shelling of the village of Selidove.

The last major victory on the front came from Russian forces last May with the capture of Bakhmut after months of costly fighting on both sides.

Ukraine's army commander in charge of the region, Oleksandr Syrsky, visited Ukrainian troops holding back Russian forces on Bakhmut's outskirts and warned of mounting Russian attacks.

"The situation is tense, requiring constant monitoring of the situation and prompt decision-making directly on the ground," Syrsky was cited as saying by the military on social media.

He said Russian forces were using kamikaze drones and electronic warfare alongside assault groups with artillery cover to break through Ukrainian defence lines outside Bakhmut.

Kyiv also said Thursday Russia had launched another barrage of Iranian-designed attack drones at Ukraine overnight, and that its air defence systems had downed 11 of 17 drones.

Officials in the Black Sea region of Odesa said the attack had damaged a school and left two police officers injured, while in the Vinnytsia region, authorities said debris from downed drones had led to a fire at an infrastructure facility.

© Agence France-Presse