"The 'peace envoys' sent by the PKK (outlawed Kurdistan Workers' Party) are a positive step along the path of peace, but they should not have been so provocative," outgoing Kurdish premier Nechirvan Barzani told reporters in the regional capital Arbil.

He was referring to celebrations in Turkey's Kurdish-majority southeast after the release on Tuesday of eight militants who crossed from Iraq to Turkey and turned themselves in as a gesture of support for government plans to expand Kurdish freedoms.

As part of the festivities, crowds brandished PKK flags and played songs praising the 25-year insurgency against Ankara.

The militants were part of a 34-strong group, also including Kurdish refugees who had lived in Iraq for years, which the PKK sent as "peace envoys" to Turkey.

"The PKK should not adopt a defiant attitude, which could halt the progress being made and would be exploited by enemies of the Kurds," Barzani said.

He said he was satisfied by the Turkish gesture to release the rebels, saying: "We hope that this project will continue to try and resolve the Kurdish problem in Turkey."

Turkish Prime Minister Recep Tayyip Erdogan was quoted as saying on Saturday that Ankara's efforts to reconcile with its Kurds had been hit by a "crisis of confidence" after the rebels were greeted with celebrations.

Erdogan said the arrival of a second such group, expected next week, has been postponed because of the festivities.

The PKK took up arms against Ankara in 1984 at the start of a conflict that has claimed about 45,000 lives. The group has long taken refuge in rear bases in Kurdish-majority northern Iraq.