A suicide attacker on a motorcycle blew himself up in a market in a northwest Pakistani town on Friday, killing 17 people and wounding 50 people, officials said.
The violence is thought to be by extremist Sunnis.
Violence by Sunni extremists against Shi’ites is common in Pakistan, a Muslim country dominated by Sunnis but home to a sizeable Shiite minority. Although attacks by Shi’ites against Sunnis do occur, such violence is not as prevalent.
Sunni extremist groups such as al-Qaeda and the Taliban often believe Shi’ites are infidels and that it is permissible or even praiseworthy to kill them. The emergence of such extremist groups in the country has added to the frequency and viciousness of attacks against Shiites.
Local government administrator Wajid Ali said the bomber struck in a market in the town of Parachinar.
Many of the dead were shoppers or people with stalls in the market, he said.
A local Taliban commander, Fazal Saeed Haqqani, claimed responsibility for the attack in Parachinar, a mostly Shiite town in a region bordering Afghanistan. He justified the attack by saying that Shiites had been attacking Sunnis.
Parachinar and the nearby region of Kurram have been plagued by sectarian violence for several years. Shiites have been the overwhelming victims.
Pakistan has seen hundreds of suicide attacks over the last five years, mostly by militants in the northwest close to the Afghan border who have given haven to Qaeda operatives and insurgents fighting in Afghanistan. The army has responded with several offensives, but have had limited success in a country where extremism is rampant.