Last month, Turkey’s defence minister, Yasar Guler,
told a Turkish newspaper that Iran had not been cooperative with Ankara in its fight against the PKK, despite Turkey's efforts to monitor the group’s movements and inform Tehran.
....
Iran denies turning a blind eye to the PKK's movements and activities. The Qandil Mountains, part of which lies inside Iran, serve as the PKK's main stronghold in northern Iraq. According to Turkish officials, PKK senior cadres have survived Turkish air strikes by taking refuge on the Iranian side.
Turkish security sources, speaking anonymously to MEE, claimed that Iran is increasingly strengthening its ties with the PKK against both Turkey and the Kurdistan Regional Government (KRG) in Iraq.