Pakistan's northwest has been the scene of sporadic bursts of sectarian violence for decades.
In the latest flareup, over 80 people were killed in clashes in the Kurram district of Khyber Pakhtunkhwa Province on November 21-23.
The violence erupted when gunmen fired on a convoy of Shi'ite Muslims. The deadly incident triggered retaliatory attacks on the Sunni Muslim community. The sides announced a seven-day cease-fire on November 24.
Troubled History
Pakistan is a Sunni-majority country. But Kurram, a mountainous district bordering Afghanistan, has a large Shi'ite population.
Decades of clashes, often over land, have left thousands of people in Kurram dead. Over 200 people have been killed since July, alone.
Sunni Muslim men gather to offer prayers during the funeral ceremony for victims who were killed in a sectarian clash in the northwestern district of Kurram on October 13.
Northwestern Pakistan has been a hotbed of militancy for decades. The emergence of Sunni and Shi'ite armed groups in the region has exacerbated sectarian tensions, experts say.
"The rise of militant groups from rival sects has transformed Kurram into a battleground for sectarian dominance," said Ihsanullah Tipu Mehsud, news director at the Khorasan Diary, a website tracking militant groups in Afghanistan and Pakistan.
Shi'a say Sunni extremist groups -- including the Tehrik-e Taliban Pakistan (TTP), Islamic State-Khorasan, and Lashkar-e Jhangvi -- are trying to exterminate or expel them from Kurram. Many of the groups have targeted Shi'a, whom they see as apostates.
In some of the worst violence in Kurram in recent decades, around 2,000 people, mostly Shi'a, were killed between 2007 and 2011 when the TTP, also known as the Pakistani Taliban, tried to overrun the district.
The Sunni community blames the violence in Kurram on the Zainebiyoun Brigade, a Shi'ite militia made up of Pakistanis who fought in Syria. The group included Shi'a from Kurram, some of whom have returned home in recent years.
Political Marginalization
Experts say the deadly sectarian violence in Kurram is also borne out of weak governance and political marginalization.
Government officials enforce a cease-fire between Shi'a and Sunni groups in Khyber Pakhtunkhwa's Kurram district in July.
Pakistan's border regions -- including Khyber Pakhtunkhwa -- have been the scene of deadly military offensives against Islamist and separatist insurgencies, and the army has been accused of committing widespread human rights abuses.
The federal government in Islamabad and the powerful military, which has an oversized role in domestic and foreign affairs, have also eroded democratic norms and institutions.
In 2019, Islamabad passed a law that granted security forces in Khyber Pakhtunkhwa sweeping powers, including detaining suspects indefinitely or without charge.
Syed Irfan Ashraf, a university lecturer in the northwestern city of Peshawar, said Pakistan's military has tried to enforce an "authoritarian governance model" in Khyber Pakhtunkhwa.
"This governance model is taking a huge toll now," he said.