Pakistan said it doesn't need international help in investigating the assassination of opposition leader Benazir Bhutto.

Link: CNN Coverage

Questions have been raised about who killed Bhutto on Thursday and how she died, as the government and medical officials have offered three different explanations of her death.

There have been calls for an independent, foreign investigation and Britain has offered to help, but Pakistan's government said it's not necessary.

The government also reiterated Saturday that Islamic militant leader Baitullah Mehsud was behind Bhutto's killing, despite his denials.

Bhutto's aides said they doubt the militant commander was behind the attack on the opposition leader. They also said the government's claim that she died when she hit her head on the sunroof of her vehicle was "dangerous nonsense."

The Pakistani official said Bhutto's party is free to exhume her body if they want.

Meanwhile, at least 44 people have been killed in three days of violence that started after Bhutto's death. Officials said there has been millions of dollars in damage. One official said rioters have destroyed more than 170 banks, more than 70 train cars and nearly 20 rail stations. At least 100 prisoners were also sprung from jails.

But officials in Bhutto's home province said there have been 44 deaths there alone. There were also reports of deaths scattered elsewhere.

Nine election offices have been destroyed by the riots -- along with the voter rolls and ballot boxes inside. The election commission has called an emergency meeting for Monday.

Pakistan's People's Party is expected to choose a new leader Sunday and decide whether to participate in Jan. 8 parliamentary elections.

World Mourns Bhutto

Although Bhutto's Pakistan People's Party lost its charismatic leader in Thursday's attack in Rawalpindi, Pakistan, French President Nicolas Sarkozy urged President Pervez Musharraf to go ahead with Pakistan's Jan. 8 parliamentary elections.

Other world leaders, on the other hand, were much more guarded on the question of proceeding with the elections aimed at restoring democracy to Pakistan.

As of Saturday, there were no plans to postpone the election despite growing violence in Pakistan and an announcement from Nawaz Sharif, another top opposition leader, that he would boycott the election.

The United States, which had staked hopes for Pakistan's stability on Bhutto-Musharraf reconciliation and encouraged Bhutto's return from exile in October, was ambiguous.

President George W. Bush called on the Pakistani people "to honor Benazir Bhutto's memory by continuing with the democratic process for which she so bravely gave her life." Asked whether the United States was confident that Pakistan could stage an election in January, State Department spokesman Tom Casey said: "Well, we're going to see what happens."

British Prime Minister Gordon Brown said he had spoken to Musharraf and urged him to "stick to the course he has outlined to build democracy and stability in Pakistan" -- though Brown did not specifically say elections should be held Jan. 8.

"This was a cowardly terrorist act designed to destabilize democratic elections," Brown said. "The international community is united in its outrage and determination that those who stoop to such tactics shall not prevail."

The United Nations Security Council summed up the world reaction by voting Thursday unanimously to condemn the killing and urge all nations to help bring those responsible for "this reprehensible act" to justice.

Bhutto May Have Foreseen Death

Word came Friday that Bhutto may have anticipated her fate months ahead of her assassination.

Bhutto complained of having inadequate security as recently as two months ago. CNN released an e-mail sent to host Wolf Blitzer on behalf of Bhutto back in October.

In the letter, Bhutto said she was "made to feel insecure" by Musharraf's "minions."

She said she'd requested police vehicles to surround her while traveling, and added that if anything happened to her, Musharraf would be responsible.

Blitzer said he was asked by Bhutto's Washington spokesman not to make the letter public unless Bhutto were to be killed. It was sent to him a little more than a week after Bhutto narrowly escaped a suicide bombing targeting her as she returned to Pakistan from exile.

Bhutto's spokesman said Bhutto didn't necessarily believe that Musharraf was trying to kill her, but that she felt that many people around him were.

Blitzer said he has no regrets about holding off on reporting about the letter, saying that he would have gone back on his word if he had used it before now.