Eight militants of the outlawed Kurdistan Workers' Party (PKK) on Monday left their camps in the mountains of northern Iraq, crossed into Turkey and turned themselves in to the authorities in a show of support for government plans to end the 25-year Kurdish conflict.

They were released on Tuesday pending trial in an unusually lenient move for a country where many end up in jail for simply expressing sympathy for the PKK, considered a terrorist group by Turkey.

The arrival of the rebels sparked ire among some, with the government facing accusations of "treason."

The main opposition Republican People's Party (CHP) charged that letting the militants free amounted to amnesty for the PKK, which took up arms in 1984, sparking a conflict that has claimed some 45,000 lives.

"This is a political, de facto amnesty carried out through the judiciary," deputy Isa Gok said.

An association of families of soldiers killed by the PKK lashed out at the government for arranging "a state ceremony to welcome the terrorists" and slammed Ankara's plans to improve Kurdish rights.

"The politicians who prepared the ground for this initiative are committing treason... The nation will hold them accountable for that," chairman Hamit Kose said.

The rebels were part of a 34-strong group, including also Kurdish refugees who had lived in Iraq for years, which jailed PKK leader Abdullah Ocalan suggested be sent as "peace envoys" to Turkey to show support for government plans to broaden Kurdish freedoms and end the conflict.

Overriding the criticism, Prime Minister Recep Tayyip Erdogan vowed Wednesday the government would press ahead with plans to resolve the conflict, but did not say what reforms it planned.

Speaking in the eastern city of Siirt, he welcomed the arrival of the rebels and voiced hope that "much more will come," Anatolia news agency reported.

However Erdogan slammed the welcome staged for the rebels by Kurdish activists at the border, calling it "an irresponsible provocation."

"We will press ahead with this process... and hopefully, we will complete it despite those incitements and provocations," he said.

Ankara categorically rejects dialogue with the PKK, but the group insisted Wednesday it should be part of any settlement.

"We did what was up to us," PKK commander Murat Karayilan told the Kurdish Firat news agency, referring to the arrival of the "peace envoys."

"We will now see what the government will do," he said. "First of all, (military) operations must stop and then a dialogue must begin."