Bhutto's body was flown from Rawalpindi, a city eight miles south of Islamabad, to Sindh Thursday night, and thousands of mourners thronged to the site and tried to touch her casket as it was carried by ambulance from her ancestral home to the mausoleum.
Bhutto's husband, Asif Ali Zardari, wept as he accompanied her coffin, draped with the green, red and black tricolour of Bhutto's Pakistan People's Party, on the 4-mile journey to the tomb in the village of Garhi Khuda Bakhsh, Reuters reported.
He then prayed there with the couple's three children, son Bilawal, 19, and daughters Bakhtawar, 17 and Aseefa, 14.
People stayed indoors and businesses were closed across much of the country, as violent protests flared and Bhutto supporters ransacked banks, stores, police stations and trains.
In Sindh, protesters tore up railroad tracks and set cars ablaze. Officials suspended train service between Karachi, the capital of Sindh, and the Punjab provinces in the east. At least 23 people were reported to have been killed in the violence.
Police in Sindh were given authority to shoot at violent protesters, but the official response was generally muted during the day, according to the Washington Post.
Meanwhile, Interior Ministry spokesman Javed Iqbal Cheema said Friday morning that Bhutto had not been killed by gunshots, but that the gunshots had missed her and instead she died when the force of the suicide bomb explosion crashed her head into a lever on the sun roof of her SUV.
No group claimed immediate responsibility for the assassination, which took place as Bhutto was waving to supporters from the sun roof of the bulletproof vehicle. But Pakistan's government said Friday that it had evidence that al-Qaida and the Taliban were responsible.
Interior Ministry spokesman Cheema said that the government had intercepted a message in which militant leader Baitulla Mehsud congratulated his people for carrying out the assassination. Cheema described Mehsud as an al-Qaida leader also responsible for an October suicide bombing attempt against Bhutto that killed more than 140 people.
President Pervez Musharraf declared a three-day period of national mourning for Bhutto, and urged calm in the country.
Many Bhutto supporters continued to blame Musharraf's government for the attack, or at least for failing to prevent it. Bhutto's death comes 12 days before Pakistanis are set to vote in contentious national parliamentary elections, in which Bhutto was running as head of her Pakistan People's Party and might have become prime minister for a third time, following terms in the 1980s and 1990s.
The Bush administration had hoped to broker an alliance of the two leaders to counter extremism in the country, but there was a history of mistrust between the two, and Musharraf had placed Bhutto under house arrest several times in the past three months, saying it was for her protection.
Many in the crowd of mourners at Bhutto's burial shouted slogans against Musharraf and the United States. "Shame on the killer Musharraf, shame on the killer U.S.," the mourners cried, according to Reuters.