“We don’t want Sinjar to be a hotbed of the P.K.K. and we don’t want to be the enemies of Turkey,” said Murad Ismael, who co-founded Yazda, a group providing support to Yazidi women raped by Islamic State militants. “But Turkey watched patiently as the Yazidi genocide unfolded and did nothing.”

“Mam Zaki was one of the first who arrived to help us,” Mr. Ismael added, using a Kurdish word that means uncle.

Nadia Murad, a Nobel Peace Prize nominee who was abducted from her village on Sinjar mountain and repeatedly raped by Islamic State fighters before escaping, wrote in an email: “Mam Zaki was a fine human who came to the rescue of Yazidis. For this we are thankful. That said, Sinjar cannot be a place for people to fight their wars.”

As many as 40,000 people are believed to have been killed in decades of conflict between Turkish soldiers and P.K.K. fighters. The P.K.K. has found refuge in Iraq’s remote mountains, and in recent years, Turkey has been fighting the group outside its borders, including carrying out airstrikes on Iraqi soil.

The continued P.K.K. presence in the Sinjar region of Iraq, the ancestral homeland of the Yazidi people, has created a complicated and increasingly tense dynamic.

Numerous armed groups have tried to lay claim to the rugged landscape and its collection of villages. The area was overwhelmingly Yazidi until 2014, when they were forced to flee the Islamic State’s advance and seek shelter in refugee camps set up hours from their homes. Years later, a sizable portion of the community is still living in those same open-air tent cities, unable to return as the struggle for control unfolds on the mountain.

One of the players in that battle for control is the P.K.K., which is also considered as a terrorist organization by the United States.