A bomb killed at least five people and wounded a Pakistani election candidate on Tuesday as he campaigned in the restive northwest, raising the death toll in the nation's bloody poll campaign to 97.
The latest attack in the town of Hangu, a flashpoint for violence between Sunni and Shiite Muslims, comes a day after the deadliest bombing so far on the election campaign.
"At least five people have been killed and several injured," police official Tahir Khan told AFP, warning that the death toll could rise.
"It is too early to determine the nature of the bomb. It might be a suicide attack or a planted bomb," Tahir Khan said.
"We are shifting the injured to a hospital and it looks like the death toll will rise," he told AFP.
Hangu police chief Mohammed Sajjad said the candidate, Syed Janan, was among the 15 people who were injured.
The attack, which came as Janan campaigned in a Hangu market, raises to 97 the number of people killed in attacks on politicians and political parties since April 11, according to an AFP tally.
Janan, seeking re-election for the assembly in Khyber Pakhtunkhwa province, is contesting Saturday's election for the right-wing Jamiat Ulema-e-Islam, a religious party in the outgoing government coalition.
A joint rally for two other candidates from the same faction of the party was bombed in the tribal district of Kurram on Monday, killing 23 people in the deadliest single attack on the campaign so far.
The Pakistani Taliban claimed responsibility, saying the target had been Munir Orakzai, a lawmaker in the national assembly who was in 2008 elected as an independent but allied to the outgoing government.
The insurgents have condemned Saturday's elections as un-Islamic and directly threatened the main parties in the outgoing coalition, the Pakistan People's Party, the Muttahida Qaumi Movement and the Awami National Party (ANP).
JUI-F and its leader, cleric Maulana Fazl-ur-Rehman, have been mediators between the authorities and the Taliban, blamed for killing thousands of Pakistanis in a domestic insurgency over the past six years.
Elections have been postponed in three constituencies where candidates have been killed. Those constituencies are in the southwestern province of Baluchistan, in Pakistan's biggest city of Karachi and in southern Hyderabad.
The vote marks the first time that a civilian government in Pakistan has served a full-term in office and handed over to another at the ballot box. The nuclear-armed country has been ruled half its life by the military.
The race has been dominated by the centre-right: opposition leader Nawaz Sharif, head of the Pakistan Muslim League-N (PML-N) and cricket star Imran Khan, looking to make a breakthrough for his Pakistan Tehreek-e-Insaf (PTI) party.