The bomber targeted the former mayor's vehicle near a bus stop in Badabher area this morning.
The former mayor was not in the car at the time of the attack.
Two persons were killed and two more injured in the attack, state-run Radio Pakistan reported.
The former mayor, who is considered close to the government, has survived several attacks in the past, officials said.
No group claimed responsibility for the attack though such incidents are usually blamed on the Pakistani Taliban.