The attack at a campaign event organized by the Awami National Party (ANP) in Yakatoot area of Peshawar also wounded at least 63 people.
The blast took place when Haroon Bilour, who was contesting elections from PK-78 constituency, arrived at the site where the ANP workers had gathered for a corner meeting. Bilour suffered serious injuries and was shifted to the hospital where he succumbed to his wounds.
There was no immediate claim of responsibility for the attack.
Haroon Bilour was the son of senior ANP leader Bashir Ahmed Bilour who was killed when a Pakistani Taliban bomber blew himself up in a party meeting in Peshawar in 2012.
The ANP, which governed the Khyber Pakhtunkhwa province from 2008 to 2013, has been a continual target of militant groups operating in the northwest. The militants killed hundreds of ANP leaders and supporters in attacks around the 2013 election.
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