DERA ISMAIL KHAN, Pakistan — The Islamic State group has claimed responsibility for suicide attack at an open-air food market that killed at least 35 people in northwestern Pakistan.

The IS-linked Aamaq news agency says Friday's attack targeted "apostate Shiites" in the Orakzai region near the Afghan border.

Sunni extremists have repeatedly targeted Shiites on both sides of the border in recent years. IS has claimed several attacks in Pakistan, where authorities deny it has an organized presence.