Awami National Party (ANP) candidate Haroon Bilour was killed on Tuesday, July 10, after a suicide bomber blew himself up at a rally by an anti-Taliban political party in Pakistan. The blast, that took place in the northwestern city of Peshawar, had killed 20 people, police and hospital officials said on Wednesday.
Bilour's father, the senior ANP leader Bashir Bilour, was killed in a suicide bombing in late 2012, in the run-up to Pakistan's last election.
The Pakistani Taliban claimed responsibility for the Tuesday attack.
"The death toll from last night's suicide attack has reached 20 while we have 65 injured, some of them in critical condition," Zulfiqar Ali Babakhel, a spokesman for Peshawar's main Lady Reading Hospital, told Reuters.
The ANP is a predominantly secular, ethnic Pashtun nationalist party, which has long competed with Islamist parties for votes in Pakistan's volatile Pashtun lands, along with the border with Afghanistan.
Islamist militants have attacked the party numerous times over the years, including in the run-up to the last election, in 2013.
The Pakistani Taliban, a loosely aligned umbrella group of several militant and sectarian bands, have been waging a war against the Pakistani state for over a decade, condemned the party in its claim of responsibility.
"The anti-Islamism of the ANP is not hidden from anyone, and this secular party martyred many members of the Muslim community during its previous government," militant spokesman Mohammad Khurasani said in a statement.
Haroon Bilour had hoped to win a provincial assembly seat in July.
Overall, violence in Pakistan has decreased in recent years after several military offensives against militant strongholds in the northwest.