Crimean Tatar leaders Akhtem Chiygoz and Ilmi Umerov, who were sentenced to prison by Russian courts on the occupied peninsula in September, have been released from custody and traveled to Turkey, Ukrainian officials, legislators, and lawyers said.
Umerov and Chiygoz were released on October 25, Ukrainian First Deputy Information Policy Minister Emine Dzheppar told RFE/RL.
Mustafa Dzhemilev, the veteran Crimean Tatar leader who is now a Ukrainian lawmaker, also told RFE/RL that Chiygoz and Umerov had been freed from Russian custody in Crimea and were on their way to Turkey.
A spokesman for Ukrainian President Petro Poroshenko, Svyatoslav Tseholko, later said on Facebook that they had arrived in Ankara.
"Two more hostages -- two political prisoners -- have obtained freedom," Nikolai Polozov, a lawyer for Chiygoz, said on Facebook.
The European Union called the development "good news" and demanded the immediate release of "all illegally detained Ukrainian citizens on the Crimean Peninsula and in Russia."
Dzhemilev told AFP he helped arrange the release by asking Turkish President Recep Tayyip Erdogan to call for the activists' release in talks with Russian President Vladimir Putin.
Erdogan has pledged to support Crimea's Tatar minority even as he has cultivated closer ties with Moscow recently.
While the Crimean Tatar leaders themselves refused to ask Putin for a pardon, Dzhemilev told AFP, eventually an order came down from the Kremlin saying the two would be "freed on humanitarian grounds."
Rights groups and Western governments have condemned the convictions, calling their trials part of a campaign of pressure and abuse conducted by Russia since it occupied and seized control of Crimea from Ukraine in 2014.
Kremlin critics say that Russia has targeted Crimean Tatars and others who opposed Moscow's takeover of the Black Sea peninsula, which followed the ouster of Moscow-friendly Ukrainian President Viktor Yanukovych by throngs of protesters in Kyiv.
Chiygoz was convicted of organizing an illegal demonstration and sentenced to eight years in prison on September 11 after what Amnesty International called a "sham trial."
Umerov was convicted of separatism on September 27 after a trial that Human Rights Watch called "ruthless retaliation" for his opposition to Moscow's takeover of the peninsula. He was sentenced to two years in a type of penitentiary called a colony settlement.
Polozov told RFE/RL that all charges against Chiygoz and Umerov have been dropped.
"Their release became possible thanks to the support of those who are not indifferent to political prisoners, who are not indifferent to Crimean Tatars," Polozov said. He said the releases were the result of "huge judicial, diplomatic, and political work" by Dzhemilev, Erdogan, and others.
"Neither Akhtem Chiygoz nor Ilmi Umerov asked for clemency or amnesty," Polozov said. "They are heroes of the Crimean Tatar people -- Ukrainian political prisoners for whom moral principles and conscience are more important than their own liberty. They are not people one can force to go on bended knee and ask for mercy from the Russian state."
In a Facebook post, Poroshenko thanked Erdogan for his role in the release of Chiygoz and Umerov, which came within weeks after Erdogan met with Putin in Ankara in late September and with Poroshenko in Kyiv on October 9.
"I thank...Erdogan for his efforts to release our heroes as we agreed in New York and Kyiv," Poroshenko said.
At a joint news conference with Poroshenko during his visit to Kyiv, Erdogan stressed that Turkey considers Crimea part of Ukraine and will continue to pay close attention to the plight of the Crimean Tatars, a Turkic-speaking, mostly Muslim minority whose members were largely opposed to the Russian takeover.
Russia seized Crimea in March 2014, sending in troops and staging a referendum denounced as illegal by dozens of countries.
Both Umerov and Chiygoz are deputy chairmen of the Mejlis, the Crimean Tatar self-governing body, which Russian authorities deemed extremist and outlawed in what rights groups and Western governments said was part of a persistent campaign of oppression targeting Crimean Tatars and other citizens who opposed Moscow's takeover.
Umerov, who suffers from diabetes and Parkinson's disease, was confined to a psychiatric hospital in August 2016, a decision condemned by Human Rights Watch as "an egregious violation of his rights."
The United States, the European Union, and others have condemned the trials of both men and called for their release.
A spokesperson for EU foreign policy chief Federica Mogherini on October 25 said that while the men's release is "good news," Russia should also release other illegally detained Ukrainians, reverse its decision to ban the activities of the Mejlis, and respect the political rights of Crimean Tatars.
The spokesperson said the EU "appreciates the efforts of all those who also worked for this outcome."
In March, the European Parliament called on Russia to free more than 30 Ukrainian citizens it said were in prison or other conditions of restricted freedom in Russia, Crimea, and parts of eastern Ukraine that are controlled by Russia-backed separatists. Most of them remain in custody.
In his Facebook post, Poroshenko said he would seek the release of all Ukrainians held by Russia.
"This issue will remain as one of the urgent ones in my talks with the world's leaders," he said, vowing to continue what he called "the joint fight for liberation of all Ukrainian citizens and their return home."
With reporting by Merhat Sharipzhan and AFP