More than 1000 Ukrainian prisoners of war and foreign fighters captured by Russian forces at the Azovstal steelworks in Mariupol have been deported to Russia to face legal proceedings, the Russian state news agency TASS says.
Some 100 foreign "mercenaries" captured following the end of the Azovstal siege last month were among the deportees, the TASS report said, adding that further Ukrainian POWs would soon be deported from Mariupol to Russia.
following weeks of fighting at the giant steelworks in the strategic Black Sea port city of Mariupol.
The Ukrainian leadership has voiced fears its prisoners could face torture or even murder at the hands of the Russians.
Russia claims there are a large number of neo-Nazis among the soldiers, a claim international experts describe as unsubstantiated.
It comes as President Volodymyr Zelenskyy says Ukrainian forces will try to "achieve a full de-occupation" of the country's territory.
"We have already lost too many people to simply cede our territory," Mr Zelenskyy said by video link at an event hosted by the Financial Times newspaper.
"We have to achieve a full de-occupation of our entire territory."
A local school destroyed by shelling in the village of Smolyanynove, east of Severodonetsk. Source: AAP / TASS/Sipa USA
French President Emmanuel Macron said in a recent interview it was important not to "humiliate" Russia, comments interpreted in Ukraine as implying it must accept some Russian demands.
Asked about Mr Macron's comments, Mr Zelenskyy said: "We are not going to humiliate anyone, we are going to respond in kind."
The governor of the Luhansk region, Serhiy Gaidai, said the defenders were finding it hard to repel Russian attacks in the centre of Sievierodonetsk, a small industrial city in the east.
"The Russians are trying with all their might to capture Sievierodonetsk and cut off the highway from Lysychansk to Bakhmut," he said in an online post.
"In the regional centre it is hard to stave off the attacks but the occupiers do not control the town."
Russia said its troops have been advancing.
Reuters could not independently verify the situation on the ground.
The fight for Sievierodonetsk has emerged as a pivotal battle, with Russia focusing its offensive might in the hope of achieving one of its stated aims - to fully capture surrounding Luhansk province on behalf of separatist proxies.
Ukrainian officials had said its forces staged a surprise counter-attack last week, driving the Russians from a swathe of the city centre.
Before that, Russian forces had seemed on the verge of encircling Ukraine's garrison in Luhansk, attempting to cut off the main road to Sievierodonetsk and its twin city Lysychansk across the Siverskiy Donets river.
Mr Gaidai said in his post that Lysychansk was under constant bombardment.
Ukraine's second city, Kharkiv, was also hit by shelling early on Tuesday and the local mayor said one person was killed.
The northeastern city came under intense bombardment in the first two months of the war but had been quieter in recent weeks after Russian forces retreated in the region.
Viacheslav Shulga, an employee at a pizzeria in the north of Kharkiv that was hit, said there had been hopes the restaurant could reopen soon after shutting at the start of the war.
"Everything is destroyed. We are removing equipment, there will be no business here for now," he said.
"It is sad as so much effort was invested in it. But someone else has decided our destiny."
Ukraine is one of the world's biggest exporters of grain, and some countries have accused Russia of creating the risk of global famine by shutting Ukraine's Black Sea ports.
The governor of the region that included the port of Mykolaiv said weekend shelling had destroyed warehouses in one of the country's largest agricultural commodities terminals.
Russia denies responsibility for the international food crisis, blaming foreign sanctions.
Russian Defence Minister Sergei Shoigu said the Russian-occupied Ukrainian ports of Berdyansk and Mariupol were ready to resume grain exports.
Ukraine says any such shipments from territory seized by Russian forces would amount to illegal looting.
Mr Zelenskyy said Ukraine was gradually receiving "specific anti-ship systems", the best way to break a Russian blockade of Ukrainian ports.
The Kremlin said that for exports to resume from Ukrainian-held ports, Ukraine must first clear them of mines.
Russia could then inspect and escort ships to international waters, Kremlin spokesman Dmitry Peskov said.