The air force jets targeted militants' hideouts on the edge of the Afghan border in the thick mountainous forests in the Wareka Mandi area of Shawal district in North Waziristan tribal region, 65 kilometres (40 miles) west of its capital Miranshah.
The official said that the killed militants included Uzbek and Afghan nationals and members of the Tehreek-i-Taliban Pakistan (TTP).
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Wednesday's attack on Ismailis was the second-deadliest in Pakistan this year after 62 Shia Muslims were killed in a suicide bombing in late January.
Pakistan has been battling a homegrown Islamist insurgency for over a decade following the late 2001 US-led invasion of Afghanistan.