"By the skin of our teeth."

That was Aidan Aslin and Shaun Pinner, captured by Russian-backed forces in Mariupol in April and sentenced to death by a court in the self-proclaimed Donetsk People's Republic.

"We just want everyone to know the good news, et cetera. Thanks to everyone that's been supporting us and whatnot. It's really, muchly appreciated."

PINNER: "Thanks to everyone."

ASLIN: "Really."

PINNER: "Can't say thank you enough."

They were among five British men released as part of the biggest prisoner swap since the conflict began in February.

Turkey helped broker the deal - involving almost 300 people: 215 of which were Ukrainians - most of them captured after the fall of the port city.

Ten foreigners were also freed following mediation by Saudi Crown Prince Mohammed bin Salman, who has maintained close ties with Russian President Vladimir Putin.

55 Russians and pro-Kremlin Ukrainians were handed back to Russia - including Viktor Medvedchuk, the leader of a banned pro-Russian party who was facing treason charges.

Yaryna Herashchenko, the girlfriend of Azov regiment fighter Ihor Davydenko who was released in the swap, spoke of her reaction on hearing the news of his release.

"Happiness, shock, tears, joy - the whole spectrum of emotions which can describe the good that took place on this earth."

"Today, he messaged me saying: "You cannot imagine what you have done to save me from going mad at the plant (Azovstal)." I told him that I had a selfish plan. I wanted to bring my heart back home. That's all."

Ukrainian President Volodymyr Zelenskiy hailed the senior Ukrainian commanders released to Turkey as "superheroes", including those of the Azov regiment who led the defense of Mariupol.

And Ukrainian police shared this photo of what they said were nine of its officers safely back on home soil.

The timing and scale of the swap came as a surprise. Pro-Russian separatists had said last month that the Mariupol commanders would go on trial.

And earlier in the day Putin had announced a partial troop mobilization, in an apparent escalation of the conflict.

The five senior commanders released will stay in Turkey until the end of the war.

Zelenskiy thanked Turkish President Tayyip Erdogan for his help after what he said had been a long and difficult fight to secure their freedom.

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