KARACHI, Pakistan — Two bombs exploded tonight near a truck carrying a former prime minister, Benazir Bhutto, on her triumphant return to Pakistan after eight years in exile, killing at least 108 people, an official said. Party workers and police said Ms. Bhutto was unhurt.

An initial small explosion was followed by a huge blast just feet from the front of the truck carrying Ms. Bhutto during a procession through Karachi. The blast shattered windows in her vehicle and set a police escort vehicle on fire.

Those traveling atop the truck with Ms. Bhutto climbed down, with one man jumping off while others climbed down.

Ms. Bhutto, who is expected to seek the premiership for an unprecedented third time and partner in ruling Pakistan with American-backed President Musharraf, was safe, her lawyer, Babar Awan, said.

Police Chief Azhar Farooqi told Dawn News that Ms. Bhutto was rushed from the area under contingency plans.

“She was evacuated very safely and is now in Bilawal House,” Mr. Farooqi said, referring to Ms. Bhutto’s residence in Karachi.

Officials at four hospitals in Karachi reported a total of 51 dead and 150 wounded.

Dr. Seemi Jamali of Jinnah Hospital said it had 19 dead from the blast, and of the 70 wounded, between 20 and 25 were in critical condition.

A man who identified himself only as Dr. Faisal of Liaqat National Hospital, reported 30 killed and 80 wounded, many critically.

Provincial Home Secretary Ghulam Mohammed Mohtaram said the main force of the blast appeared to be taken by the police vehicle.

Footage from the scene of the blasts showed bodies on the ground, lying motionless, under a mural that read “Long Live Bhutto.”

Pools of blood, broken glass, tires, motorcycles, and bits of clothing littered the ground near where the bombs went off. Men moved the injured away from the fires near the blast site. One bystander came upon a body, checked for signs of life, and moved on, presumably to find more who could be saved.

The injured were carried in stretchers from ambulances and rushed them into a hospital emergency room, while others carried the wounded in their arms. Many of the wounded were covered in blood, and some had their clothes ripped off.

Medical personnel began to tend to the injured while dozens of people walked through in a daze.

After the blasts, pickup trucks filled with men rushed away from the scene and others began to run, but many more stayed and milled in between the police vehicle and those of the procession.

Ms. Bhutto had been traveling on a truck equipped with a bulletproof glass cubicle to the tomb of Pakistan’s founding father, Mohammed Ali Jinnah, to give a speech. More than 150,000 jubilant supporters had surrounded the convoy carrying Ms. Bhutto through Karachi amid massive security.

Authorities had urged her to use a helicopter to reduce the risk of attack. But Ms. Bhutto, hated by radical Islamists because she supports the American-led war on terrorism, brushed off the concerns.

“I am not scared. I am thinking of my mission,” she had told reporters on the plane. “This is a movement for democracy because we are under threat from extremists and militants.”

She was squeezed between other party officials at the front of the truck rather than in the bulletproof cubicle toward the rear. Armed guards escorted the truck.

Ms. Bhutto recently courted controversy in Pakistan by saying that she would cooperate with the American military in targeting Osama bin Laden, and authorities warned that Islamic militants could launch suicide attacks and roadside bombings against her.

Asked about such threats on Wednesday in Dubai, Ms. Bhutto said Islam forbids suicide bombings and attacks on her. “Muslims know if they attack a woman they will burn in hell,” she said.

The government of Sindh province, of which Karachi is the capital, had appealed to Ms. Bhutto to abandon plans for a snail-paced grand procession through Karachi, saying it would leave her vulnerable. The government said the main threat was from Taliban and Al Qaeda

Ms. Bhutto had received a rapturous welcome from the tens of thousands of supporters, who craned from tree branches and foot bridges to glimpse her return to Pakistan.

The big turnout — Ms. Bhutto even claimed 3 million — reflected the former prime minister’s enduring political clout despite eight years in exile. But rivals claim her pro-American line and possible alliance with the country’s military ruler will damage her chances for a comeback.

“I feel very, very emotional coming back to my country,” Ms. Bhutto said at the airport, as thousands of supporters of her Pakistan People’s Party massed outside amid a sea of the party’s red, green, and black flags.

When she descended the steps of the commercial jetliner, Ms. Bhutto was in tears.

“I counted the hours, I counted the minutes and the seconds, just to see this land, to see the grass, to see the sky. I feel so emotionally overwhelmed,” Ms. Bhutto, who wore a white headscarf and clutched prayer beads in her right hand, said.

“And I hope that I can live up to the great expectations which people here have,” she said.

She said 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,”

Ms. Bhutto, 54, fled Pakistan in the face of corruption charges in 1999. It would take a constitutional amendment for her to be prime minister again; Pakistani law bars leaders from seeking a third term.

The security precautions failed to dampen the spirit of huge crowds.

Hundreds of buses and other vehicles festooned with billboards welcoming her back were parked bumper-to-bumper along the boulevard from the airport to the city center.

Supporters including representatives of Pakistan’s minority Christian and Hindu communities and Baluch tribesmen with flowing white turbans, walked toward the airport, while groups of men performed traditional dances, beat drums or shook maracas along the way.

Ms. Bhutto paved her route back in negotiations with General Musharraf, who seized power in a 1999 coup. General Musharraf, whose popularity has waned as violence by Islamic radicals has risen, is promising to give up his command of Pakistan’s powerful army if he secures a new term as president.

The talks have yielded an amnesty covering the corruption cases that made Ms. Bhutto leave Pakistan in the first place, and could see the archrivals eventually team up to fight Al Qaeda and the Taliban.

Prime Minister Shaukat Aziz welcomed Ms. Bhutto’s return, saying it would improve the political and help democracy to “flourish.”

But General Musharraf, who had urged Ms. Bhutto to delay while he dealt with legal challenges to his continued rule, stayed silent.

A White House spokeswoman, Dana Perino, declined to comment directly on Ms. Bhutto’s return but said America wanted “a peaceful, democratic Pakistan, an Islamic state that is a moderate force in the region, and one that can be an ally to help us fight extremism and radicalism.”

Before boarding her flight from Dubai, Ms. Bhutto told reporters that her homecoming felt like a miracle.

“I hope that, as this miracle is happening, that a miracle will happen for the impoverished and poverty-stricken people of Pakistan who are desperate for change, who want safety, who want security, who want opportunity, who want empowerment and employment,” she said.

Outside Karachi airport, police with batons charged one group of supporters who approached the VIP terminal. But with the crowds swelling, they later relaxed the cordon and let thousands of flag-waving PPP partisans to gather around the building.

A senior police officer at the airport, Raza Hussain Shah, said 20,000 officers were deployed there and along the route into the city. Officials said police bomb squads and thousands of paramilitary troops and party volunteers also were on hand.

Ms. Bhutto, whose two elected governments between 1988 and 1996 were toppled amid allegations of corruption and mismanagement, hopes to lead her secular, liberal party to victory in parliamentary elections in January.

General Musharraf has seen his popularity plunge since a failed attempt to oust the country’s top judge in the spring. The rapprochement with Ms. Bhutto appears aimed at boosting his political base as he vies to extend his rule.

He easily won a vote by lawmakers October 6 to give him a new five-year presidential term. The Supreme Court, however, has ruled that General Musharraf’s victory can only become official once it rules on challenges to the legality of his re-election.