Former premier Benazir Bhutto narrowly escaped a suicide bombing that shattered her homecoming procession and killed 126 people hours after she returned to Pakistan from exile pledging to fight extremism and promote democracy.

Two explosions late Thursday struck near a truck carrying Bhutto, shattering its windows, but police and officials of her party said she was not injured and was hurried to her house. An Associated Press photo showed a dazed-looking Bhutto being helped away.

Officials at six hospitals in Karachi reported 126 dead and 248 wounded, making it one of the deadliest bombings in Pakistan's history.

Bhutto flew home earlier Thursday to lead her Pakistan People's Party in January parliamentary elections after eight years in exile, drawing cheers from supporters massed in Pakistan's biggest city in a sea of the party's red, green and black flags. The police chief said 150,000 were in the streets of Karachi, while other onlookers estimated twice that.

The throngs reflected Bhutto's enduring political clout, but she has made enemies of Islamic militants by taking a pro-U.S. line and negotiating a possible political alliance with Pakistan's military ruler, President Gen. Pervez Musharraf.

Authorities had urged her to use a helicopter to reduce the risk of attack amid threats from extremists sympathetic to the Taliban and al-Qaida, but she brushed off the concerns.

"I am not scared. I am thinking of my mission," she had told reporters on the plane from Dubai.

At the airport in Karachi, she told AP Television News she was fighting for democracy and to help this nuclear-armed country of 160 million people defeat the extremism that gave it the reputation as a hotbed of international terrorism.

"That's not the real image of Pakistan. The people that you see outside are the real image of Pakistan. These are the decent and hardworking middle-classes and working classes of Pakistan who want to be empowered so they can build a moderate, modern nation," she said.

Leaving the airport, Bhutto refused to use a bulletproof glass cubicle that had been built atop the truck taking her to the tomb of Pakistan's founding father, Mohammed Ali Jinnah, to give a speech.

Her procession had been creeping toward the center of Karachi for 10 hours, as dancing and cheering supporters swarmed around the truck, when a small explosion erupted near the front of the vehicle — about halfway from the airport to the tomb.

That was quickly followed by a larger blast, setting an escorting police van on fire and breaking windows in Bhutto's vehicle. Party members on top of the truck scrambled to the ground.

The former premier had just gone to a downstairs compartment in the truck for a rest when the blast occurred, said Christina Lamb, Bhutto's biographer.

"She knew she was a target ... she was worried that the lights were going off, the street lights, and that snipers could be on tops of buildings and bridges," she told Sky News.

"Luckily the bus had a downstairs enclosed compartment for her to go and rest in, and she just happened to be there when it went off, so she wasn't on top in the open like rest of us, so that just saved her," she said.

Police officer Raja Umer Khitab said evidence at the scene suggested it was a suicide bombing. He said it destroyed two police vans escorting Bhutto's truck."

In the aftermath, bodies lay motionless in the street, under a mural reading "Long Live Bhutto" on the side of the truck. Pools of blood, broken glass, tires, motorcycles and bits of clothing littered the ground. One bystander came upon a body, checked for signs of life, and moved on.

Some of the injured were rushed on stretchers into a hospital, and others were carried by rescuers in their arms.

Karachi has a history of violent attacks by Islamic militants, but this appeared to be the deadliest yet. In April 2006, a suicide bombing killed 57 people, including the top leaders of a Sunni Muslim group.

The United States, the United Nations and the European Union condemned the attack.

"Extremists will not be allowed to stop Pakistanis from selecting their representatives through an open and democratic process," said Gordon Johndroe, foreign affairs spokesman for President George W. Bush.

Richard Haass, president of the New York-based Council on Foreign Relations, said the attack reveals "one of the fundamental realities of Pakistan today is that the government is not in total control of the country."

The bloodshed marred what had been a jubilant day for Bhutto. The 54-year-old politician wept for joy after her arrival.

"I dreamt of this day for so many months, and years. I counted the hours, the minutes and the seconds just to see this land, sky and grass. I'm so emotionally overwhelmed," Bhutto told APTN at the airport, dressed in green with a white head scarf to match the national flag of Pakistan.

Bhutto had paved her route back to Pakistan through negotiations with Musharraf, a longtime political rival whose rule she has often condemned but whose proclaimed mission to defeat Islamic extremism she shares.

Their talks yielded an amnesty covering the corruption charges that made Bhutto leave Pakistan, and could lead to them forming a political alliance seeking to unite moderates in January parliamentary elections for a fight against militants allied with al-Qaida and the Taliban.

Musharraf won re-election to the presidency in a controversial vote this month by the nation's lawmakers, but the victory is being challenged in court. The Supreme Court will rule soon on whether he was eligible to compete in the vote, since he also holds the post of army chief.

If he is confirmed for a new five-year presidential term, Musharraf has promised to quit the military and restore civilian rule — a step critics say he should have taken earlier.

Bhutto became leader of the Pakistan People's Party more than two decades ago after the military's 1979 execution of its founder, her father Zulfiqar Ali Bhutto, a populist prime minister still exalted by many Pakistanis as the finest leader in the country's 60-year history.

She served twice as the democratically elected primer minister between 1988 and 1996 — the first female premier in the Muslim world — but both governments fell amid allegations of corruption and misrule. After Musharraf seized power, she was charged with illegally amassing properties and bank accounts overseas while in power and she left Pakistan.