The mountains of northern Iraq have for years been a sanctuary for Kurdish militants fighting a decades-long insurgency against the government in neighboring Turkey.

The group, the P.K.K., made its declaration days after its long-imprisoned leader urged the movement to disarm and disband, but there are still many questions about the prospects for ending 40 years of deadly conflict.

Residents in Diyarbakir, Turkey's largest Kurdish-majority city, said on Sunday that the outlawed Kurdistan Workers Party's (PKK) decision to heed its jailed leader's call for peace was correct and prosperity would follow if the decades-old conflict ended.