The gunmen in a car opened indiscriminate fire at the security personnel at Mangag check post in lower Kurram Agency, killing two of them.
Those killed were identified as Shoaib Hussain and Warkhan Gul while another security personnel Mir Alam was critically wounded, officials said.
The injured personnel was immediately shifted to Agency Headquarters Hospital.
The accused were later nabbed as security was tightened in the region after the incident.
