Zulfiqar Ali Baba Khel, the spokesperson of the Lady Ready Hospital of Peshawar, confirmed that 13 persons died and 47 others sustained injuries in the blast.
Chief of Peshawar police, Qazi Jamil, said that the provincial information secretary of the Awami National Party (ANP) Haroon Bilour was among the killed persons in the suicide attack.
A suicide bomber exploded his explosives-laden vest when Haroon Bilour was meeting party workers at a public meeting in Yakatoot area of Peshawar, the capital of Pakistan's northwest Khyber Pakhtunkhwa province, the police officer said.
The bomber managed to reach near the slain politician when party workers were celebrating his arrival with fireworks.
Police, security forces and rescue teams rushed to the site and shifted the bodies and injured to the Lady Reading Hospital.
The Bomb Disposal Squad of police said that around eight to ten kilograms of explosives along with one kilogram of ball bearings was used in the attack.
No group has claimed responsibility for the attack yet.
Bashir Bilour, the father of Haroon Bilour and a senior political leader of the ANP, was also killed in a suicide blast during an election campaign in Peshawar in 2012.
Haroon Bilour was contesting for a provincial assembly seat PK-78 in the country's July 25 general elections.
The ANP is a Pashtun nationalist party from Pakistan's Khyber Pakhtunkhwa province and had representation in the provincial assembly, and also in the upper house and the lower house of the country's parliament.
Leaders of all major political parties condemned the attack and urged authorities to ensure the security of the politicians contesting the elections.
Chief Election Commissioner of Pakistan said it is a conspiracy to disrupt the process for the free and fair elections.