The incident occurred as the bomber rammed his motorcycle with the vehicle of tribal elder Habibullah Wazir in Hangu district bordering Kurram agency, police officer Sajjad Khan said.
But, the condition of Habibullah is yet to be confirmed.
The injured were shifted to Hangu's District Headquarter Hospital.
No militant group has yet claimed responsibility for the attack.
Separately, two officials of the bomb disposal squad were killed while defusing an explosive device at a school in Swabi district of Khyber Pakhtunkhwa, officials said.