25 others were also wounded when the car bomb aimed at Pakistani security forces went off on the outskirts of Peshawar on Sunday, AFP reported.
The bomb targeted a security force convoy on the main road to Kohat, near the tribal belt where Pakistani militants have strongholds.
Reports say acts of violence have claimed the lives of more than 6,000 people in Pakistan over the past six years.
Thousands of Pakistanis have lost their lives in bombings and other militant attacks since 2001, when Pakistan entered an alliance with the United States in the so-called war on terror.
Thousands more have been displaced by the wave of violence and militancy sweeping across the country.