Turkey's intelligence services said on Monday PKK militants had withdrawn from four key bases in northern Iraq, confirming a move announced by the Kurdish group last week.
The decision comes two months after Turkey voted through a bill offering limited amnesty for PKK militants in a major step in the peace process seeking to end decades of deadly violence.
"The PKK evacuated the Hebat, Yajk, Sabri and Sason hideouts in Baze, in the Metina region of northern Iraq, on October 8," security sources said in a statement carried by state news agency Anadolu.
It was widely understood to be from the National Intelligence Organisation (MIT).
On Thursday, the PKK said it had withdrawn all its armed forces "both within and outside Turkey that could be considered near the border...a few days ago".
That included a withdrawal "from four war tunnels and positions in Metina, west of Zap", a strategic border area that in the past was frequently targeted by the Turkish military.
Ankara has repeatedly said that all disarmament moves by the PKK must be verified by Turkish intelligence, which is a key part of the law passed in August.
Such verification must ensure an end to all military activities and the handover of weapons and ammunition stockpiles before the legislation's legal measures can be implemented.
In May last year, the PKK announced it was disbanding following a historic call by their jailed leader Abdullah Öcalan.
Two months later, its militants took part in a historic disarmament ceremony in northern Iraq where they began symbolically destroying their weapons.
The Turkish statement said the evacuation would allow the process to move forward, ultimately allowing former militants to return home.
"Following the cessation of PKK activities in all areas, social reconciliation will be achieved with organisation members who will return to Turkey in the later stages of the process, benefiting from the law," it said.
"The goal is to ensure the integration of PKK members into society through integrated programmes in many areas such as education and the economy."
'Concrete measures'
Cihan Aydin, co-chair of the Human Rights Association, welcomed the PKK's withdrawal, telling AFP on Thursday it was "a very important indicator" of the group's determination to see an end to the conflict.
He said the move should be met with a "positive" response from the Turkish state, notably through democratisation reforms.
"Concrete goodwill measures will strengthen confidence in the process and make it more resilient," Aydin said.
Earlier this month, President Recep Tayyip Erdogan reiterated the government's determination to achieve a "terror-free Turkey".
But on Thursday, the PKK accused Ankara of failing to pursue the process with sufficient sincerity and speed, despite the militants fulfilling their own commitments.
As part of the initiative, Turkey has established four sub-committees to oversee practical aspects of the PKK's decision to dissolve itself, including one focused on disarmament that Öcalan will join.
Senior Erdogan adviser Mehmet Ucum said Öcalan will join the disarmament sub-committee, while stressing this would not mean he would be released.
The 77-year-old has played a key role in advancing efforts to end the conflict from his cell on İmralı Island near Istanbul, where he has spent the past 27 years serving life in solitary confinement, with the PKK leadership repeatedly demanding he be freed as part of the process.
The new law does not specify what will happen to him.