Russia has begun handing over the remains of Ukrainian fighters killed in the Azovstal steelworks, the scene of the last stand in the battle for Mariupol.
Dozens of bodies from the complex and its maze of tunnels are being taken to Kyiv for DNA testing, according to an Azov Regiment spokeswoman and one of its military leaders.
The regiment was among the Ukrainian forces holed up alongside civilians in the steelworks as it was bombarded by Russian attacks for about three months.
Ukrainian forces in Azovstal surrendered in May amid dire conditions, handing Russia control of the southern city that had endured the worst onslaught of the war.
It is unclear how many bodies may still be inside the plant.
The fate of many of the fighters who were allowed to leave is also uncertain and President Zelenskyy has said 2,500 of them are being held prisoner.
The first official confirmed swap of military remains since the war began took place on Saturday in the Zaporizhzhia region, according to Ukrainian officials.
Each side got back 160 bodies.
Anna Holovko, a spokeswoman for the Azov Regiment, said all the Ukrainians were from Azovstal and that at least 52 are thought to be from the regiment.
A former Azov leader now in Kyiv, Maksym Zhorin, confirmed that bodies from the steel plant were among those exchanged.
Sievierodonetsk heroes ‘do not give up’
Russia is now focussed on the Donbas – a region in Ukraine’s east that it is determined to capture after failing to seize other areas, such as the capital Kyiv.
Sievierodonetsk, a city of about 100,000, is key to that plan and intense battles are rumbling on.
Ukraine’s President Zelenskyy was near the front line earlier this week. In his nightly address on Monday, he said: “Our heroes do not give up positions in Sievierodonetsk.
“In the city, fierce street fighting continues.”
The country’s defence ministry said Russia was adding troops and equipment as it tries to capture the city – the largest remaining Ukrainian-held city in Luhansk – one of the two regions that make up the Donbas.
The battle appears finely poised with “the situation changing from hour to hour”, according to Oleksandr Stryuk, head of the Sievierodonetsk administration.
Mr Zelenskyy also warned that Russian wanted to take the city of Zaporizhzhia, in the southeast, home to more than 700,000 people, a move that could see the enemy moving closer to the centre of Ukraine.
“In the Zaporizhzhia region … there is the most threatening situation there,” the president said.
Both the UK and US are sending precise long-range missile systems to Ukraine so it can take on the Russian artillery that’s causing so much damage in the Donbas.
President Putin warned on Sunday that new targets would be attacked if the West supplied such weapons. The same day, missiles hit Kyiv for the first time in over a month.
Britons could face death penalty
On Monday, two people were killed in shelling in Donetsk and Luhansk as Russian forces fired at more than 20 communities, said Ukraine’s military. Russia denies targeting civilians.
The defence ministry also said Russia was advancing towards Sloviansk, a city about 53 miles (85km) west of Sievierodonetsk.
“The front line is under constant shelling,” Donetsk regional governor Pavlo Kyrylenko said on television.
“The enemy is also shelling near Lyman with the aim of wrecking our defensive positions and advancing on Sloviansk and Kramatorsk. There is also shelling of Svyatohirsk with the same aim.”
Attempts are ongoing to evacuate people from the area, including from Sloviansk which has about 24,000 people still there.
“People are now understanding, though it is late, that it is time to leave,” said Mr Kyrylenko.
In other developments, three British men said to have been fighting as mercenaries for Ukraine are being put on trial in the separatist Donetsk People’s Republic, said the president of the self-declared breakaway region.
They could be executed if convicted of charges that include trying to seize power.
Many foreigners with military experience have travelled to Ukraine from around the world to fight in the war.