British police say blast killed Pakistan's Bhutto

ISLAMABAD (Reuters) - British police investigating the murder of Pakistani opposition leader Benazir Bhutto concluded she was killed by a head injury caused by the impact of a bomb blast, not by a bullet, drawing skepticism from her close aides.

The British High Commission released a summary of their report on Friday, which backed the government's version of the assassination in Rawalpindi city on December 27.

Bhutto's assassination heightened fears of instability in nuclear-armed Pakistan. It also delayed an election that may lead to U.S. ally President Pervez Musharraf's downfall if a hostile parliament emerges from the February 18 vote.

The British report also said Bhutto was probably killed by a lone assassin, who fired shots and detonated explosives, and was not attacked by two people as many Pakistanis had speculated.

"The only tenable cause for the rapidly fatal head injury in this case is that it occurred as the result of impact due to the effects of the bomb-blast," British government pathologist Nathaniel Cary said in the report.

Cary said he suspected Bhutto hit her head against the sunroof, backing an explanation the government had also given.

Scotland Yard's conclusion drew skepticism from members of Bhutto's Pakistan People's Party who were with her when she was killed, and runs counter to what senior hospital officials say they were told privately by doctors who attended to Bhutto.

"We find it difficult to agree with the report about the cause of death, that she was not killed by the assassin's bullet," Sherry Rehman, the PPP spokeswoman who prepared Bhutto's body for burial, told Reuters.

The PPP is expected to ride a wave of sympathy at the polls and, while it isn't a presidential election, Musharraf's position could be in jeopardy if the new parliament seeks his impeachment.

Campaigning so far has been low key, as many candidates are wary of leaving their homes because of the security threat.

DIVERTING ATTENTION?

Two-time prime minister Bhutto was killed as she stood up through the sunroof of her armored land cruiser to wave to supporters as she left an election rally.

The government said she was killed when the force of the bomb blast smashed her head into a lever on the sunroof.

The controversy over how she was killed fuelled suspicion government agencies were involved.

The confusion was created, according to a Pakistani lawyer who requested anonymity, "to keep people thinking about something else rather than who did it."

The government and the U.S. Central Intelligence Agency (CIA) say Baitullah Mehsud, an al Qaeda-linked militant chief based on the Afghan border, was behind Bhutto's killing.

Musharraf has denied the involvement of himself, intelligence agencies or the military, and asked Scotland Yard to join the probe after doubts arose over the government's explanation.

But it was only tasked with investigating how Bhutto was killed, not who was behind it.

"She was assassinated in front of everybody. We need the culprits, we need the killers, we need to know who had a motive," said Babar Awan, a senior PPP official and leading lawyer.

Pakistani authorities announced on Thursday two "important suspects" had been arrested in Rawalpindi.

They arrested two other suspects last month, including a 15-year-old boy who admitted being a back-up suicide bomber.

The British report said it was difficult to assess exactly how the assassination was carried out due to an inadequate search of the scene, which was hosed down hours after the attack that killed more than 20 people, and the absence of an autopsy.

No autopsy was carried out, at the request of Bhutto's family. Her husband, Asif Ali Zardari, said at the time an autopsy was unnecessary as it was clear Bhutto had been shot.

Scotland Yard investigators interviewed doctors who attended to Bhutto at Rawalpindi General Hospital, but there have been reports that they came under pressure beforehand.

The team that attended to Bhutto said she died from "an open head injury, with depressed skull fracture leading to cardiopulmonary arrest", but did not say what caused the wounds.

(Writing by Simon Cameron-Moore; Editing by Katie Nguyen)