Police official Shafqat Malik told AFP news agency that "according to our initial investigation, it was a suicide attack and Haroon Bilour was the target". Mr Bilour was taken to hospital but later succumbed to his injuries.
A case over the incident has been registered at police station Agha Mir Jani Shah with SHO Wajid Ali as the complainant.
The ECP said that elections have been postponed due to the death of the PK-78 candidate, adding that the new schedule for the said constituency will be announced soon.
"I am also ready to sacrifice my life for your rights, but I request you to exercise restraint", Bilour's 16-year-old son Daniyal, who was wounded in the bombing, told supporters at his home.
According to police, a suicide attacker entered a corner meeting of the ANP leader and blew himself up.
He said around eight kilograms of explosive material was used in the attack.
The politicians facing security threats included the former Khyber Pakhtunkhwa (KP) chief ministers Jamiat Ulema Islam-Fazl (JUI-F) Akram Durrani and ANP's Ameer Haider Hoti. The military waged a major offensive against militants in the Swat Valley in 2009.
On July 4, NACTA Director Obaid Farooq while briefing a sub-committee of the Senate Standing Committee on Interior had said, "We have received as many as 12 threat alerts which are about leadership of political parties, including the Pakistan People's Party (PPP) and Pakistan Muslim League-Nawaz (PML-N), and six personalities can be targeted during elections".
The body of Haroon Bilour was later shifted to Bilour House where ANP workers gathered in great numbers to pay respect to their deceased leader.
Peshawar hospital official Zulfiqar Babakhel confirmed the updated death toll.
Operation To Rescue Boys Trapped In Thai Cave Resumes
On Sunday, officials decided they could no longer wait, saying conditions were "as flawless as they will be" for a rescue attempt. Two divers are helping each one make his way through very narrow tunnels that twist and turn, and filled with dark muddy water.
Trump to Announce His Supreme Court Nominee Tonight
The White House said Trump has interviewed four potential picks, all of whom are federal appeals court judges . Departing his New Jersey golf club on Sunday afternoon, Trump told reporters he was still making up his mind.
Man City Sign African Star For £60m
But the Premier League champions remained keen on Mahrez, who scored 13 goals in 41 appearances for Leicester last season. The midfielder who has been unsettled at Leicester following failed moves last season is now undergoing medicals at City.
Wilshere leaves Arsenal for London rival West Ham
Michail Antonio is one of three players West Ham United are prepared to offload if the right offer is made, according to a report. The midfielder will try to revive his career and earn an England recall after leaving Arsenal as a free agent this month.
Serena sets sights on eighth Wimbledon title
Williams needs to beat two seeded opponents to win her 24th major title, tying Margaret Court's record for Grand Slam wins. The victor of the Williams and Giorgi match battles Bertens or Goerges in the semifinals. "She's great player.