Islamabad, Pakistan (CNN) -- A blast Monday near a political rally left 18 people dead in a Pakistan tribal region, a local government official said.
The strike occurred in the Kurram district, Riaz Khan said, and also wounded at least 56 people. Khan said the blast was detonated remotely and 10 kilograms of explosives were used.
The explosion occurred during a rally staged by the Jamiat Ulema-e-Islam-Fazal Ur Rehman group, a right-wing religious party with sympathies for the militant Taliban movement.
The incident occurred as Pakistanis prepare to go to the polls Saturday for national elections.
The Pakistani Taliban claimed responsibility. It said it attacked because one of the candidates, Munir Orakzai, has handed over members of the mujahedeen to the United States.
"We will never forgive him nor leave him alive," a statement from Pakistani Taliban spokesman Ihsan Ullah Ihsan said.
Jan Achakzai, a spokesman for Jamiat Ulema-e-Islam-Fazal Ur Rehman, said more than 2,000 people were attending the rally. Dr. Anayatur Rehman, who works at the hospital that received the bodies, said 18 people died.
Achakzai said more than 50 people were injured and two candidates received minor injuries.
"We will continue our politics of peace and reconciliation in Pakistan's tribal region despite these cowards' attacks," Achakzai said.
Violence has marred the run-up to the elections.
The anti-Taliban Awami National Party and the Muttahida Quami Movement and their personnel also have been targeted recently.
Maulana Fazal Rahman, the head of Jamiat Ulema-e-Islam-Fazal Ur Rehman, condemned the attack and said it prompted him to underscore the importance of national unity and deplore sectarian hatred.
"We cannot replace Sunnis with Shias, nor Shias with Sunnis, but we can remove hatred between various sects, ethnicities, linguistic groups," he said.