Ukrainians freed by pro-Russian rebels during a prisoner exchange are welcomed by relatives at the Boryspil airport outside Kiev on 29 December 2019. (AFP)

Ukraine and Russia-backed separatists in the country’s war-torn east exchanged 200 prisoners on Sunday, swapping detained fighters for civilians and servicemen held captive in some cases for years in two breakaway regions.

“It’s wonderful, I’m so happy,” Ukrainian President Volodymyr Zelensky told journalists after greeting former prisoners at Boryspil airport near Kiev.

A plane carrying 76 captives, including 12 military personnel and 64 civilians, was met by a crowd of relatives, some holding flowers and balloons.

Family members, some with children, rushed to embrace the former prisoners with tears and shouts of joy.

“Most of all I want to relax after all this and forget as soon as possible what was happening there,” Anatoliy Semerenko, one of released civilians, told reporters.

Among those swapped were Stanislav Aseyev and Oleg Galazyuk, two journalists who contributed to the Ukrainian service of the US-funded Radio Free Europe/Radio Liberty.

Kiev also handed over to separatists five riot policemen suspected of killing protesters during a pro-Western uprising in 2014 as part of the swap, sparking public outrage.

Russian President Vladimir Putin, German Chancellor Angela Merkel and French President Emmanuel Macron hailed the “positive” swap.

The exchange came after Putin and his Ukrainian counterpart Zelensky held their first face-to-face talks in Paris on 9 December and agreed measures to de-escalate Europe’s only active war.

Earlier on Sunday prisoners filed off coaches at the Mayorske checkpoint in the eastern Donetsk region, many carrying plastic bags stuffed with their belongings, as gun-toting uniformed soldiers and ambulances were on standby.

Victoria, 24, said she had been held for three years after being convicted of “state treason.”

Another woman being handed to Kiev sported a handwritten sign on her clothing: “My country is Ukraine!”

The swap, which was overseen by monitors from the Organization for Security and Co-operation in Europe, came three months after Ukraine carried out a long-awaited exchange with Russia of 35 prisoners each.

The previous prisoner swap between Kiev and separatists took place in 2017.

Ties between Ukraine and Russia were shredded after the bloody 2014 uprising ousted a Kremlin-backed regime.

Moscow went on to annex Crimea and support insurgents in eastern Ukraine who launched a bid for independence in 2014. Since then more than 13,000 people have been killed in the conflict.

The release of the riot police has raised concerns in Ukraine, with many fearing the country is being pushed to pay too high a price for the swap.

The riot policemen are suspected to have been involved in the bloody crackdown on protesters in 2014. Some 100 demonstrators were shot dead during the uprising.

“What Ukrainians have been fighting for is going down the drain,” filmmaker Oleg Sentsov, who was released in the September prisoner exchange, said on Facebook.

“This country has no future,” Volodymyr Golodnyuk, whose 19-year son was killed in the uprising, said on his Facebook page.

“It was a difficult decision,” Zelensky told the press in the airport.

“But we were able to return those who are alive,” he added.

The European Union said “we take note” of the exchange of riot policemen.

“We expect all accusations will continue to be investigated and the parties concerned to ensure that those responsible are brought to justice,” they said in a statement.

Since coming to power in May, comedian-turned-president Zelensky, 41, has sought to kickstart a peace process to end the conflict.

At the Paris summit, the leaders sought to revive accords signed in Minsk in 2015 that call for the withdrawal of heavy weapons, and the restoration of Kiev’s control over its borders, among other conditions.

But many doubt whether Putin genuinely wants to settle the conflict.

He has said that if Kiev gets back control of the border in the east, residents of separatist-held territories could be targeted.

Zelensky’s peace plan has also been strongly criticized by war veterans and nationalists.