Turkey is holding five members of a Kurdish "peace group" who crossed into the country from Iraq, reports say.
Prosecutors have reportedly called for charges to be brought against members of the banned Kurdistan Workers Party.
The rest of the -strong group - who had handed themselves in near Silopi on Monday - were reportedly released.
The PKK's -year war for autonomy in south-east Turkey has left dead, and Turkey is currently seeking a negotiated end to the insurgency.
The Kurdish peace group was made up of both PKK fighters from their stronghold in Iraq's Qandil mountains, and refugees from the Makhmour camp south of Mosul.
They were greeted as they crossed the border into Turkey on Monday by thousands of supporters waving PKK flags, before being taken in for questioning by Turkish authorities.