KIEV, June 14 - Two Ukrainians jailed in Russia have been released and sent home, in a prisoner swap between the two countries, Deutsche Welle reported. Two alleged pro-Russian soldiers fighting in Ukraine were reported to have gone in the opposite direction.

The swap involved two people who Ukraine claims are political prisoners, as well as two pro-Russian fighters who were allegedly promoting the pro-Moscow cause in the Ukrainian capital.

Russian President Vladimir Putin's decision to grant pardons to Yuriy Soloshenko and Gennady Afanasyev was not explained by the Kremlin.

However, Moscow said separately that two Ukrainian reporters - Yelena Glishchinskaya and Vitaly Didenko - who were accused of spreading pro-Russian propaganda in Ukraine, had also been released

The Kremlin press office also said the releases were "made possible by thanks to the active involvement of Vikor Medvedchuk" - a Ukrainian whose personal friendship with Putin is said to have been instrumental in allowing the exchanges to go ahead.

On their arrival in Kiev on Tuesday, both Afanasyev and Soloshenko were sent to hospital for treatment for chronic ailments that required immediate care.

Their release was greeted by Ukrainian President Petro Poroshenko, who met the pair.

"My dear boys, welcome home!! Poroshenko told the two after they had arrived at the hospital, adding: "We did it!"

The pair's cases were not as widely known as that of Ukrainian fighter pilot Nadiya Savchenko who was released as part of a swap 19 days earlier.

The 25-year-old photographer Afanasyev captured by Russia's security service in Crimea, in May 2014, along with filmmaker Oleg Sentsov and two others who were accused of terrorism. He was jailed for seven years in December 2014.

That sentence was reduced after he agreed to cooperate with investigators and pleaded guilty to all charges. He later recanted his confession and claimed it was forced out of him under torture.

Details about 73-year-old Yuriy Soloshenko are less clear.

Savchenko, who was traded for two alleged Russian soldiers, became celebrated as a symbol of Ukrainian resistance to Russia, having been elected as a member of former Prime Minister Yulia Tymoshenko's party back in 2014.

She was arrested soon after while serving in a volunteer battalion in eastern Ukraine and, in March this year, was convicted of ordering mortar fire that killed two Russian journalists.

The 35-year-old Savchenko, who took up her place in parliament at the end of May, accuses the current Ukrainian government of failing to meet public expectations and has called for early elections. (dw/ez)