An administration official who asked not to be named because he was not authorized to talk to reporters told RFE/RL that gunmen riding two motorcycles opened fire at the men in Hassu Khel village of Mir Ali town.
There was no immediate claim of responsibility for the attack.
Attacks on Pakistani security forces in the restive Balochistan Province bordering Afghanistan and Iran and the tribal districts bordering Afghanistan have increased over the past few months.
Zubaidullah Dawar, a director at the Pakistan Housing Authority Foundation within the Ministry of Housing and Works, and Malik Nematullah, a local tribal elder and officer at Health Department of Khyber Pakhunkhwa Province, died “on the spot,” the administration official said.
Farman, the third victim, reportedly died on his way to the hospital in Bannu.
Nizam, a police official at Mir Ali police station, told RFE/RL that the attack took place at 11 a.m. local time near Eidgah, a place where Muslims offer Eid al-Fitr prayers.
A case was filed and sent to the Counterterrorism Department of the police, he added.
Both officials were attending an Eid al-Fitr celebration marking the end of the holy month of Ramadan in their hometown, Nizam said.
When contacted, Shafiullah Gandapur, police chief of North Waziristan tribal district, declined to comment.
Mohsin Dawar, a lawmaker representing North Waziristan in Pakistan’s parliament, “strongly” condemned the attack on Twitter.
On May 17, a Pakistani soldier was killed in a roadside bomb attack in Mir Ali in North Waziristan.