Heavy fighting raged around the eastern Ukrainian town of Pisky on Thursday as Russia pressed its campaign to seize all of the industrialised Donbas region, while to the west Kyiv accused Moscow of using a nuclear plant to shield its artillery.

An official with the Russia-backed Donetsk People's Republic said Pisky, on the frontlines just 10 km (6 miles) northwest of provincial capital Donetsk, was under control of Russian and separatist forces.

"It's hot in Pisky. The town is ours but there remain scattered pockets of resistance in its north and west," the official, Danil Bezsonov, said on Telegram.

Ukrainian officials denied that the heavily fortified town, a key to the defence of Donetsk, had fallen. Reuters was unable to verify the battlefield accounts.

The Donbas region comprised of Luhansk and Donetsk provinces became Moscow's main objective after retreating from the capital Kyiv at the start of the war in February. Luhansk is now almost completely under Russian control but Donetsk is still holding out.

Oleksiy Arestovych, a Ukrainian presidential adviser, said in an interview posted on YouTube that Russian "movement into Pisky" had been "without success".

Luhansk regional Governor Serhiy Gaidai, interviewed on Ukrainian TV, said Russia had sent increasing numbers of mercenaries into the region, including from the Wagner private security firm.

"We once had peaceful Ukrainian towns. Now we have been thrust into the Middle Ages ... People are now leaving because they are afraid of freezing in the coming winter," he said.

NUCLEAR PLANT

Ukraine accused Russia on Wednesday of killing at least 13 people and wounding 10 with rockets fired from around a captured nuclear power plant in the centre of the country, in the knowledge it would be risky for Ukraine to return fire.

"The cowardly Russians can't do anything more so they strike towns ignobly hiding at the Zaporizhzhia atomic power station," Andriy Yermak, President Volodymyr Zelenskiy's chief of staff, said on social media on Wednesday.

Ukraine says around 500 Russian troops with heavy vehicles and weapons are at the plant, where Ukrainian technicians continue to work.

The town Ukraine says Russia targeted - Marhanets - is one Moscow says its foes have used in the past to shell Russian soldiers at the Zaporizhzhia plant, which they seized in March.

Ukraine's military said Russia also bombarded several other areas in the Zaporizhzhia region. Russia has not commented on the Ukrainian allegations and Reuters could not independently verify Kyiv's version.

Ukraine and Russia have accused each other of imperilling the plant, Europe's largest nuclear complex, with attacks nearby.

The Group of Seven leading industrialised countries on Wednesday told Russia to hand back the plant to Ukraine, after the United Nations atomic energy watchdog sounded the alarm over a potential nuclear disaster.

CHINA BACKS RUSSIA

Russia on Wednesday received powerful endorsement from China of its rationale for the Feb. 24 invasion of Ukraine.

Beijing's ambassador to Moscow, Zhang Hanhui, accused Washington of pushing Russia into a corner with repeated expansions of the NATO military alliance and support for Ukraine's alignment with the European Union.

Washington's "ultimate goal is to exhaust and crush Russia with a protracted war and the cudgel of sanctions," Zhang was quoted as saying.

Ukraine's military reported Russian forces shelled some 28 towns in the northeast, southwest and south including the Kharkiv, Donetsk and Kherson regions on Wednesday. Ukraine's general staff said counterattacks forced Russian troops to retreat in most of them.

Ukrainian presidential adviser Arestovych said dozens of civilians had been killed by Russian shelling on Wednesday.

Moscow says it does not deliberately target civilians in what it calls its "special military operation" aimed at safeguarding its security against NATO expansion.

Ukraine and the West accuse Moscow of waging an unprovoked imperial-style war of aggression.

The war has crushed Ukraine's economy, but there was some relief on Wednesday when overseas creditors backed Kyiv's request for a two-year freeze on payments on almost $20 billion in international bonds. That should avert a messy default.

Ukrainian Prime Minister Denys Shmyhal said the deal would save his country almost $6 billion.

Reuters