Pakistani opposition leader Benazir Bhutto is dead following a shooting and a suicide bomb attack on her vehicle as she left a public rally in Rawalpindi. She was 54.

As Bhutto waved to supporters from a car's sunroof, an attacker rushed toward the vehicle and opened fire. Her security adviser, Rehman Malik, said the leader was shot in the neck and chest.

The gunman then detonated an explosive device, killing at least 22 other people.

• Read about the life of Benazir Bhutto: 1953-2007

Bhutto was rushed to Rawalpindi General Hospital for surgery but succumbed to her wounds. Wasif Ali Khan, a member of Bhutto's party, said "at 6:16 p.m. she expired."

On Friday, Bhutto's body was being flown to her ancestral cemetery in Garhi Khuda Baksh, a small village in Sindh province. Her coffin was accompanied by her husband and three children.

She's expected to be buried Friday next to the grave of her father, former prime minister Zulfikar Ali Bhutto, who was removed from power by the military in 1977 and executed.

A doctor who treated Bhutto said one bullet struck the back of her neck, hit her spinal column and exited through the side of her head. Another bullet went through the back of her shoulder and out her chest.

Moments before her death, she had told an ecstatic crowd of supporters that she would fight Islamic militants with Pakistan's own army, rather than depend on foreign soldiers.

"Why should foreign troops come in? We can take care of this, I can take care of this, you can take care of this," she said.

The FBI sent a bulletin to police agencies around the world that suggested al Qaeda had claimed responsibility for the attack, citing information from Islamist websites.

The bulletin also said al Qaeda's second-in-command, Ayman al-Zawahri, may have planned the attack, according to a law enforcement official who spoke to The Associated Press on condition of anonymity.

But Bhutto had several enemies in Pakistan, and had accused Pakistani President Pervez Musharraf's government of doing little to ensure her security at political rallies.

After her death, Bhutto's body was taken out of the hospital, her casket carried aloft by supporters.

Pakistan elections should go on: Harper

Canadian Prime Minister Stephen Harper offered condolences to Bhutto's family, to the families of the other victims of today's attack, and to the Pakistani people.

"We condemn this attack in the strongest possible terms. This was an abhorrent act of terror. We hope that the government of Pakistan will act to bring the perpetrators to justice."

Harper told reporters in Calgary that the Pakistan election scheduled for Jan. 8 should continue as planned.

"This cannot be allowed to permit any delay in the return of Pakistan to full democracy -- something the people of Pakistan have been waiting for, for far too long," he said.

U.S. President George Bush also condemned the attack.

"The United States strongly condemns this cowardly act by murderous extremists who are trying to undermine Pakistan's democracy," he said from Crawford, Tex.

"We stand with the people of Pakistan in their struggle against forces of terror and extremism. We urge them to honour Benazir Bhutto's memory by continuing the democratic process for which she so bravely gave her life."

United Nations Secretary-General Ban Ki-moon called the assassination an "assault on stability", while the UN Security Council went into consultations to discuss the killing.

Three days of mourning

Pakistani President Pervez Musharraf announced three days of mourning and appealed for calm amid word of violent protests erupting across the volatile South Asian nation.

"This is the work of those terrorists with whom we are engaged in war," he said in a nationally televised speech. "Today, after this tragic incident, I want to express my firm resolve ... we will not rest until we eliminate these terrorists and root them out."

Bhutto's supporters at the hospital in Rawalpindi smashed glass doors and stoned cars and many chanted slogans against Musharraf, accusing him of complicity in the assassination.

In Rawalpindi, the site of the attack, Bhutto's supporters burned election posters from the ruling party and attacked police, who fled from the scene. And in the northwestern city of Peshawar as well other areas, angry supporters have taken to the streets chanting slogans against Musharraf.

The death has also thrown the campaign for the Jan. 8 election into chaos. Musharraf has called a high-level emergency meeting to discuss the government's response.

Pakistani opposition leader and former prime minister Nawaz Sharif said on Thursday his party would boycott the election.

"The PML(N) is boycotting the election after the assassination of Benazir Bhutto," Sharif told a news conference in Islamabad, referring to his party.

"Free elections are not possible in the presence of Musharraf... Musharraf is the root cause of all problems."

'She was the party'

Terrorism expert Eric Margolis, who advised Bhutto on security and became friends with her, told CTV Newsnet that her death will throw her party's future into turmoil.

"Bhutto's party which was the largest party in Pakistan -- the Peoples Party -- has now been decapitated," said Margolis. "She dominated the party. She was the party. It was a very personalized party. She does not really have a strong No. 2."

The Pakistan Peoples Party was founded by Bhutto's father, Zulfikar Ali Bhutto, who served as a president and prime minister of Pakistan in the 1970s.

Bhutto lost power in a 1977 coup to Gen. Zia Ul-Haq, then the chief of the army staff whom Bhutto himself had appointed. Bhutto was executed in 1979 for allegedly ordering the murder of a political opponent.

Benazir, the oldest of the Bhutto children, vowed to continue the work of her father and won a majority in parliamentary elections in November 1988, at the age of 35.

By 1990, President Gulam Ishaq Khan had dismissed her government on charges of corruption -- charges Bhutto denied. Three years later, Bhutto won the prime ministership once again.

Her government would be dismissed again on corruption allegations in 1996. That same year, her brother Murtaza, also politically active, was shot to death under murky circumstances.

Facing corruption charges that she claimed were politically motivated, Bhutto left Pakistan in 1999, the same year Musharraf deposed Sharif.

Bhutto returned to Pakistan from exile in October 2007 and was campaigning ahead of the January elections. At the rally celebrating her return last October, more than 140 people were killed in another suicide blast. Bhutto was not hurt and remained defiant despite the threats on her life.

Margolis says Bhutto was aware of the dangers she faced and knew that attending rallies was a risk.

"She always said to be a politician and to do her populace politics, she had to be seen, and to move, and to go into the streets. That's the Pakistani style," he told CTV Newsnet.

"She was taking extreme precautions to protect herself, but the point was if she didn't show herself and stayed in seclusion, she would have lost a lot of her popular appeal. She was a street politician, rallying huge numbers of people was her stock and trade."

At the rally in Rawalpindi on Thursday, Bhutto herself explained her motivations:

"I put my life in danger and came here because I feel this country is in danger. People are worried. We will bring the country out of this crisis."