The blast targeted the meet organised at Doaba in Hangu district by JUI leader Mufti Syed Janan, who is contesting polls to the Khyber-Pakhtunkhwa assembly.
Janan escaped unhurt, officials and witnesses were quoted as saying by TV news channels.
Witnesses said at least 10 people were killed and several injured persons were lying at the site of the blast.
No group claimed responsibility for the attack, which came a day after 24 people were killed in a bombing at an election meeting organised by JUI leader Munir Orakzai in Kurram tribal region.
The banned Pakistani Taliban claimed that attack.
Pakistan has witnessed a spike in violence ahead of the May 11 general election.
The Tehrik-e-Taliban has vowed to target secular parties like the Pakistan People's Party and Awami National Party.
Image: Akhtar Soomro/Reuters