Pakistan said Friday it would step up its probe into the assassination of Benazir Bhutto after a U.N. report blamed security forces for failing to protect her -- accusations dismissed as a "pack of lies" by an aide to ex-President Pervez Musharraf.
Bhutto, a former prime minister, was killed in a Dec. 27, 2007, gun and suicide-bomb attack as she was leaving a rally in Rawalpindi city, where she was campaigning to return her Pakistan People's Party to power in elections after returning from nearly nine years in self-imposed exile.
The slaying was the latest in a long line of high-profile political assassinations in Pakistan and convulsed the country, which was then ruled by unpopular military-backed ruler Musharraf and battered -- as now -- by al-Qaida and Taliban violence. Supporters of Bhutto immediately hinted that Musharraf or his allies in the powerful and largely unaccountable security forces may have played a role.
The three-member U.N. panel, which was not tasked with unmasking the killers, said Bhutto's death could have been avoided if Musharraf's government and security agencies had taken adequate measures. It also found that the probe into her death was deliberately hampered by intelligence agencies.
The report, issued Thursday, was highly critical of a decision made within hours of the killing to hose down the crime scene and not to conduct an autopsy.
The report was hailed by the PPP, which now governs Pakistan and is led by President Asif Ali Zardari, Bhutto's widower. Zardari aide Farahnaz Ispahani said "the report will pave the way for a proper police investigation and possible penal proceedings."
Presidential spokesman Farhatullah Babar said the report backed up the PPP's belief that Musharraf or his allies were responsible for Bhutto's death. He said the probe "was a shot in the arm into ongoing investigations," into her death.
But Musharraf aide Rashid Qureshi insisted the U.N. report was based on rumors and that Musharraf -- currently living abroad -- was not responsible.
"This chief U.N. investigator was not the relative of Sherlock Homes," Qureshi told The Associated Press. "It is a pack of lies."
He added that Bhutto exposed herself to the risk even after the head of the country's most powerful spy agency, Inter-Services Intelligence, warned her not to attend the rally because of threats of an attack.
Musharraf's government blamed Baitullah Mehsud, a Pakistani militant commander with links to al-Qaida. Officials at the U.S. Central Intelligence Agency also reportedly said Mehsud, who was killed in a missile strike last August, was the chief suspect.
Bhutto was a secular politician with strong links to Western governments and a vocal critic of Islamist militants.
The U.N. commission said Musharraf's government, though tracking threats against Bhutto, did little more than pass them on to her and provincial authorities and did not act to neutralize them or ensure "that the security provided was commensurate with the threats."
Bhutto's party provided extra security, but the arrangements "lacked leadership and were inadequate and poorly executed," it said.
"Ms. Bhutto faced threats from a number of sources," the commission said. "These included al-Qaida, the Taliban, local jihadi groups and potentially from elements in the Pakistani Establishment" -- the customary way people here refer to the country's powerful military and intelligence apparatus.
The U.N. said the police probe lacked direction and commitment, and that it went after "lower level operatives," not higher-ups.
The commission said Inter-Services Intelligence conducted parallel investigations, gathering evidence which was only selectively shared with the police.
"The commission believes that the failure of the police to investigate effectively Ms. Bhutto's assassination was deliberate," the report said. "These officials, in part fearing intelligence agencies' involvement, were unsure of how vigorously they ought to pursue actions, which they knew, as professionals, they should have taken."
Five people have been accused by authorities of involvement in the assassination -- although they are not believed to be the masterminds and the investigation is ongoing. Officials have said a final charge-sheet against them would only be submitted in court after the U.N. report was examined. A hearing was scheduled for April 21 for the five, jail official Mohammed Zafar said.
The commission urged Pakistani authorities to carry out a "serious, credible" criminal investigation that "determines who conceived, ordered and executed this heinous crime of historic proportions, and brings those responsible to justice."
The U.N. secretary-general agreed to appoint a commission to assist Pakistan by determining the facts and circumstances of Bhutto's death and it began work on July 1, 2009, conducting more than 250 interviews and reviewing hundreds of documents, videos, photographs and documentary material.
Under terms agreed to by the U.N. and the Pakistani government, Pakistani authorities would determine any criminal responsibility.
Associated Press Writers Edith M. Lederer in New York and Chris Brummitt in Islamabad contributed to this report.