Ukrainian President Viktor Yanukovych pardoned Sunday a close ally of jailed former premier Yulia Tymoshenko as several thousands rallied in Kiev to protest his policies amid rising political tensions.
Yuriy Lutsenko walked free from a prison in northern Ukraine after Yanukovych pardoned the 48-year-old former interior minister under pressure from European Union and the opposition.
Yanukovuch has however earlier ruled out pardoning his top nemesis Tymoshenko and his decree Sunday made no mention of her.
"Yanukovych signed a decree pardoning six convicted people, including Ukraine's former interior minister Yuriy Lutsenko and Ukraine's former environment minister Georgy Filipchuk," his office said in a statement.
The imprisonment of Tymoshenko and Lutsenko has drawn strong criticism from the United States while EU leaders have refused to sign an important trade agreement with Kiev until they were released.
The European Union hailed the pardon for Lutsenko and Filipchuk, another Tymoshenko ally, but indicated it expected more from the Ukrainian authorities.
"A first but important step to deal with selective justice," Stefan Fule, the European commissioner for enlargement and European neighbourhood policy, said on Twitter.
Secretary General of the Council of Europe Thorbjorn Jagland added: "I trust that Ukraine will also follow the judgement of the Court in the case of former Prime Minister Yulia Tymoshenko."
Lutsenko, sporting an ethnic embroidered shirt, said upon release from the Menskaya corrective labour facility in the country's north that he would seek a meeting with Tymoshenko and remain in politics.
"I will be in the streets, among people," he told reporters after being greeted by his wife Irina and friends.
He also addressed a rally of more than 7,000 people in Kiev called by the opposition to demand Yanukovych's resignation.
"I am sincerely happy that I will finally be among those who like me are dreaming about an independent and European Ukraine," he told the rally by phone.
The rally was called after pro-government lawmakers in the parliament last week split off to hold a session at an alternative venue amid a weeks-long standoff with the opposition which described the rare walkout as a coup attempt.
At the rally, the opposition called for the release of all "political prisoners".
"We will fight for the release of Yulia Tymoshenko because after Yuriy Lutsenko was freed Yulia Tymoshenko should be freed too," said Arseniy Yatsenyuk, who represents Tymoshenko's party in the parliament.
Yanukovych's statement said the decree was in line with reforms of the country's criminal legislation "aimed at humanising legal norms and reducing the number of people held in custody".
Lutsenko was arrested while walking his dog in Kiev in 2010 and had been sentenced to remain in prison until the end of 2014 after being convicted of abuse of office and embezzlement.
The pardon came after Ukraine's high court last week rejected Lutsenko's appeal.
Lutsenko's health has gravely deteriorated while in detention. His lawyers say he had contracted hepatitis, and is now suffering from pancreatitis and other illnesses. In January, he underwent an operation on his intestine.
Lutsenko's lawyer Alexei Baganets called the pardon "an act of clemency in relation to a man who was illegally arrested, charged and convicted".
Lutsenko's detention led to entreaties to Yanukovych from special envoys of the European Parliament monitoring mission to Ukraine, former Polish president Aleksander Kwasniewski and former president of the European Parliament Pat Cox.
Yanukovych in March had promised that he would consider pardoning Lutsenko, while ruling out a similar move for Tymoshenko.
"I have known Yuriy Lutsenko for a long time and I am sorry for him as a person. He is suffering from the stupidities he committed," Yanukovych had said.
Analysts said Tymoshenko is unlikely to be freed any time soon.
"Yanukovych is unlikely to release her taking into account the long sentence she's got and Yanukovych's attitude towards her," said Vladimir Fesenko, head of the Penta think tank.
He said that by pardoning Lutsenko, Yanukovych wanted to show Brussels that Ukraine was still keen to move closer to Europe.
Tymoshenko, who lost a heated presidential election to Yanukovych in 2010, was jailed for seven years in 2011 on charges of overstepping her authority while prime minister by agreeing a gas deal with Russia.