A blast killed 24 people and injured 70 in the northwestern Pakistani city of Parachinar on Sunday, officials said, and a banned Sunni Islamist group claimed responsibility for the attack.
"This is revenge for the killing of Muslims by the Syrian president and Iran," said Ali bin Sufyan, spokesman for Lashkar-e-Jhangvi (LeJ), an Islamist group whose sectarian ideology is closely aligned with Islamic State. He was speaking to Reuters by phone.
Earlier this week Reuters reported that a Shiite unit of Pakistani fighters known as the Zeinabiyoun were joining the war against Islamic State in Syria. Many come from Parachinar, which has a large Shiite population, unusual in Sunni-majority Pakistan.