Police have regularly struggled to control violence in Kurram, which was part of the semi-autonomous Federally Administered Tribal Areas until it was merged with Khyber Pakhtunkhwa in 2018.
The ceasefire deal came after a delegation from the provincial government held talks with the Shiite community on Saturday and met the Sunni community on Sunday.
A security official in the provincial capital of Peshawar told AFP the negotiators’ helicopter had come under fire as it arrived in the region, although no one was harmed.
Once a truce was agreed, “we can begin addressing the underlying issues,” provincial Law Minister Aftab Alam Afridi said earlier Sunday.
Last month at least 16 people, including three women and two children, were killed in a sectarian clash in Kurram.
Previous clashes in July and September killed dozens of people and ended only after a jirga, or tribal council, called a ceasefire.
The Human Rights Commission of Pakistan said 79 people were killed between July and October in sectarian clashes.
Several hundred people demonstrated against the violence on Friday in Pakistan’s two largest cities, Karachi and Lahore.