Four prominent Kurdish activists, including award-winning ex-MP Leyla Zana, have been freed from Turkish jail pending an appeal.
Zana's sentence had been confirmed in a retrial earlier this year
A Turkish court ordered the release on Wednesday after a state prosecutor called for their sentences - imposed in 1994 - to be quashed.
Their trials had been widely condemned by human rights groups.
The European Commission welcomed the decision as a sign that reforms in Turkey were gathering pace.
"Today's decision is a sign that the implementation of political
reforms, which Turkey has been introducing in the past two years, is
gaining ground," said Guenther Verheugen, the commissioner for enlargement.
He added that the commission was hoping that a future trial would be conducted fairly.
Turkish Justice Minister Cemil Cicek said those who opposed Turkey's entry into the EU should think again.
"This is the last bargaining chip in the hands of those who were seeking excuses in Turkey's EU bid," Anatolia news agency quoted him as saying.
"The Turkish legal system has done its part, now it's the others' turn."
Ms Zana rose to prominence in Turkey in 1991, when she spoke in Kurdish during her oath of allegiance to parliament.
Within three years, she was in jail - along with fellow MPs Orhan Dogan, Hatip Dicle and Selim Sadak - for collaborating with the PKK.
She became known as a high-profile dissident when she was awarded the European Parliament's Sakharov Peace Prize in 1995 - a year after her conviction.
The BBC's Jonny Dymond in Istanbul says Ms Zana has become a symbol both of peaceful protest and of flaws in the Turkish judicial system.
Our correspondent says the crowd went wild when she and her fellow prisoners came out of jail, with several hundred people dancing and holding up fabric in the Kurdish colours of red, green and yellow.
"The Kurdish people are proud of you," the crowds shouted, hurling bouquets of flowers at the four as they made their way through.
'Rule of law'
Ms Zana's lawyer told the BBC that her release was a victory after a 10-year struggle.
"It's obvious that Turkey operates under the rule of law," he said.
Her appeal will begin on 8 July.
The four had their sentences confirmed in an earlier retrial this year, but European institutions warned that their continued imprisonment would affect Turkey's efforts to join the EU.
The decision coincided with the first transmission by a Turkish state broadcaster of a Kurdish language programme.
The move, which satisfies another key EU demand, follows decades during which the use of Kurdish was banned, publications were proscribed and broadcasters prosecuted.
Also on Wednesday, the European Court of Human Rights has been hearing an appeal by the former leader of the outlawed paramilitary Kurdistan Workers' Party (PKK), Abdullah Ocalan, who is currently serving a life sentence on a remote Turkish island.
The European Commission is to issue a report in October on whether Turkey is ready to start EU entry talks.