Gunmen on Sunday targeted vehicle of Muttahida Majlis Amal (MMA) candidate Akram Khan Durrani.
Police said the attackers managed to flee after the attack. The candidate remained unhurt in the incident.
It was the second attack on Durrani who earlier targeted in Bannu district of Khyber Pakhtunkhwa during election campaign.
At least four people were killed in the attack and several others injured.