The suicide attacker with explosive-laden motorcycle hit the Frontier Constabulary (FC) convoy at a traffic signal in Peshawar's Hayatabad area, police said.
Two Frontier Corps men, including a major, were killed in the attack, SSP Operation Sajjad Khan said.
Ten others, including passersby, were injured in the blast near Bagh-e-Naran chowk in Hayatabad.
Two vehicles that were part of the convoy were completely damaged in the blast.
Security personnel cordoned off the area after the explosion as rescue services shifted the injured to Hayatabad Medical Complex.
TTP spoksman Khurasani in a statement mailed to media said slain major Jamal Sheren was on their hit list.
The terror group vowed to carry out more attacks on FC troops.
The attack comes a day after the Pakistan army announced it had launched an operation in the Khyber tribal region to rout Islamic State militants.