LAHORE, Pakistan (CNN) -- A suicide attacker targeted a police truck Thursday, killing 24 people -- most of them police -- in the Taliban-dominated area of North West Frontier province, police sources said.
The attack happened in Mangora, located in the Swat district where Pakistan recently deployed 2,500 troops to maintain law and order.
Police officer Amjad Khan told the Associated Press the blast hit a platoon of 43 Frontier Constabulary troops in a truck near the police district headquarters.
The region has increasingly become a stronghold of local Taliban militants.
Fears over Pakistan's stability were raised last week when a suicide bombing in Karachi, targetting a convoy carrying former Pakistani prime minister Benazir Bhutto, killed 136 people.
Bhutto Thursday told CNN that she intends to visit her constituency of Larkana on Saturday amid security fears after last week's bombing.
Last Thursday's attack happened hours after her arrival in the southern port city of Karachi.
Bhutto told CNN International that the decision to return to Larkana, her ancestral village, was "a very big dilemma."
"I do not want to risk the life of another single person, but my colleagues and I have thought long and hard and we feel that if we will not take the risks of traveling then in fact the militants and their sponsors, organizers and financers will succeed in stopping the democratic proces," she said.
No one has claimed responsibility for the October 18 suicide attack, but Pakistan suspects al Qaeda may have been behind the bombing. A senior U.S. official said the attack "bears the hallmarks" of an al Qaeda attack, and noted the group has threatened Bhutto before.
Bhutto returned to Pakistan last week after eight years in self-imposed exile. She intends to seek a third term as prime minister, possibly under a powersharing deal with Pakistan's President, Gen. Pervez Musharraf.
Bhutto, who was not injured the attack, told CNN she has written a letter to Musharraf calling for an independent inquiry into the blasts.
"We have to work together to eliminate terrorism," she said.
Bhutto said it was important to uncover not just those responsbile for carrying out the attacks, but also those financing and organising them.
She has blamed Islamic militants for the attacks, and has also pointed the finger at security services and elements within the government.
On Thursday a new chief investigator was appointed to probe last week's suicide attack, after Bhutto claimed the previous officer was complicit in the torture of her husband in 1999, The Associated Press reported.
Saud Mirza, the chief of criminal investigations at Karachi, will now head the team examining the attack.
Bhutto has demanded international experts be called in to help in the investigation, but this has been rejected by the government E-mail to a friend
CNN's Mohsin Naqvi contributed to this report.
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