The incident comes as authorities probe reports that Pakistani Taliban chief Hakimullah Mehsud died in a US missile strike elsewhere in the northwest.
Official Abdul Malik says the bodies were displayed Tuesday in the Inayat Kali area in Bajur tribal region.
Bajur was the focus of a previous Pakistani army offensive that seemed largely successful in clearing out the Taliban and Al-Qaeda. But insurgents have recently staged a comeback.
Malik also said security forces had killed eight more militants in overnight raids in the region.
Keep up with the latest business news from the region with the Emirates Business 24|7 daily newsletter. To subscribe to the newsletter, please click here.
Follow Emirates 24|7 on Google News.