More than 250 Ukrainian troops surrender as Kyiv orders Mariupol to yield

• Ukrainian soldiers, many wounded, bussed to Russian-held towns
• 'Defenders of Mariupol are heroes of our time'- Ukraine military
• Putin says he sees no threat from Finland, Sweden joining NATO
• Explosions hit Lviv, fighting reported in numerous areas

Ukraine's military said on Tuesday it aimed to evacuate its remaining soldiers from their last stronghold in Mariupol, as fighters that have held out for 82 days began to surrender, heralding the end of Europe's bloodiest battle in decades.

Reuters saw buses leave the huge Azovstal steelworks overnight and five of them arrive in the Russian-held town of Novoazovsk. In one, marked with the Latin letter 'Z' that has become the symbol of Russia's assault, wounded men were lying on stretchers three bunks high. One man was wheeled out, his head tightly wrapped in thick bandages.

Video released by the Russian ministry of defence showed fighters leaving the plant, some being carried on stretchers, others with their hands up to be searched by Russian troops.

Russia said 256 Ukrainian fighters had "laid down their arms and surrendered", including 51 severely wounded. Ukraine said 264 soldiers, including 53 wounded, had left the metal plant, and efforts were under way to evacuate others still inside.

"The 'Mariupol' garrison has fulfilled its combat mission," the General Staff of Ukraine's Armed Forces said in a statement.

"The supreme military command ordered the commanders of the units stationed at Azovstal to save the lives of the personnel ... Defenders of Mariupol are the heroes of our time."

The surrender appears to mark the end of the battle of Mariupol, where Ukraine believes tens of thousands of people were killed under months of Russian bombardment and siege.

The city now lies in ruins. Its complete capture is Russia's biggest victory of the war, giving Moscow total control of the coast of the Sea of Azov and an unbroken stretch of eastern and southern Ukraine about the size of Greece.

But it comes as Russia's campaign has faltered elsewhere, with its troops around the city of Kharkiv in the northeast lately retreating at the fastest pace since they were driven out of the north and the area around Kyiv at the end of March.

Authorities on both sides gave few clues about the ultimate fate of Mariupol's last defenders, with Ukrainian officials discussing the prospect of some form of exchange for Russian prisoners but giving no details.

"We hope that we will be able to save the lives of our guys," Ukrainian President Volodymyr Zelenskiy said in an early morning address. "There are severely wounded ones among them. They're receiving care. Ukraine needs Ukrainian heroes alive."

Ukrainian Deputy Defence Minister Hanna Malyar said 53 injured troops from the steelworks had been taken to a hospital in Russian-controlled Novoazovsk, some 32 km (20 miles) to the east, and another 211 people were taken to the town of Olenivka, also in an area controlled by Russian-backed separatists.

All of the evacuees would be subject to a potential prisoner exchange with Russia, she added.

HEAVY SHELLING REPORTED
Mariupol is the biggest city Russia has captured since its Feb. 24 invasion, giving Moscow a clear-cut victory for the first time in months, during which its campaign in Ukraine has mostly faced military disaster against an underestimated foe.

In a statement released late on Monday, the Azov Regiment, the Ukrainian unit that had held out in the steelworks, said it had achieved its objective over 82 days of resistance by making it possible for Ukraine to defend the rest of the country.

"In order to save lives, the entire Mariupol garrison is implementing the approved decision of the Supreme Military Command and hopes for the support of the Ukrainian people," the Azov Regiment said in a social media post.

In an accompanying video, one of the unit's senior commanders, Denys Prokopenko, called the decision to save the lives of his men "the highest level of overseeing troops".

The United Nations and Red Cross say thousands of civilians died under Russia's siege of the once prosperous port of 400,000, with the true toll uncounted but certain to be Europe's worst since wars in Chechnya and the Balkans in the 1990s.

For months, Mariupol's residents were forced to cower in cellars under perpetual bombardment, with no access to food, fresh water or heat and dead bodies littering the streets above. Two incidents in particular - the bombings in March of a maternity clinic and of a theatre where hundreds of people were sheltering - became worldwide emblems of Russia's tactic of raining down devastation on population centres.

Thousands of civilians are believed to have been buried in mass graves or makeshift pits dug in gardens by their neighbours. Ukraine says Moscow sent mobile cremation trucks to erase evidence of civilian deaths, and forcibly deported thousands of residents to Russia.

Moscow denies targeting civilians or deporting them, and says it has taken in refugees. It says it is now restoring normal life to the city, part of the Donbas region it claims on behalf of separatists it has backed since 2014.

UKRAINE ADVANCES
Elsewhere, Ukrainian forces have been advancing in recent days at their fastest pace for more than a month, driving Russian forces out of the area around Kharkiv, Ukraine's second largest city.

Ukraine says its forces have reached the Russian border, 40 km north of Kharkiv. They have also pushed at least as far as the Siverskiy Donets river 40 km to the east, where they could threaten supply lines to Russia's main advance in the Donbas.

Russia is still pressing that advance, despite taking heavy losses in a failed river crossing last week. Zelenskiy's office said on Tuesday the entire front line around Donetsk was under constant massive shelling. Ukraine's general staff said Russian forces were reinforcing and preparing to renew their offensive near Slovyansk and Drobysheve, southeast of the town of Izium.

Areas around Kyiv and the western city of Lviv, near the Polish border, have continued to come under Russian attack. A series of explosions struck Lviv early on Tuesday, a Reuters witness said. One missile hit a military facility but there were no casualties, according to Zelenskiy's office.

A village in Russia's western province of Kursk bordering Ukraine came under Ukrainian fire on Tuesday, regional Governor Roman Starovoit said. Three houses and a school were hit but there were no injuries, he said.

PUTIN CLIMBDOWN OVER NATO
In response the invasion, historically non-aligned Finland and Sweden have announced plans to join NATO, bringing about the very expansion of the Western alliance that President Vladimir Putin had long invoked as one of the main justifications for ordering his "special military operation" in February.

After weeks in which Russia threatened unspecified retaliation, Putin appeared to abruptly climb down, saying in a speech on Monday that Russia had "no problems" with either Finland or Sweden, and that their NATO membership would not be an issue unless the alliance sent more troops or weapons there.

Foreign Minister Sergei Lavrov said on Tuesday there would be "probably not much difference" if Finland and Sweden joined NATO, since they had already been cooperating in the alliance's military exercises.