The body of slain opposition leader Benazir Bhutto was flown to her home in southern Pakistan for burial in the family tomb Friday as anger over her assassination exploded into deadly rioting.

Bhutto's husband and three children accompanied the coffin as it arrived by helicopter in Naudero in southern Sindh province where she was to be interred next to her father.

As Pakistan began three days of mourning, Pakistan's ARY television network reported that Al-Qaeda had claimed responsibility for Thursday's gun and bomb attack in the northern city of Rawalpindi which killed Bhutto.

Interior ministry spokesman Javed Cheeema said that it was "unaware" of an Al-Qaeda claim but pointed the finger at "the same extremist elements who have been perpetrating acts of terrorism in the country in the past."

Grief-stricken supporters burned vehicles and buildings, blocked roads and screamed abuse at President Pervez Musharraf as anger over her death triggered violence that left at least 10 people dead.

Bhutto, 54, was leaving a rally where she had been campaigning for January 8 general elections when a suicide bomber shot her in the neck. He then blew himself up, killing around 20 people.

Her death stunned world leaders who urged calm and warned that extremists must not be allowed to destabilise the nuclear-armed nation before the vote.

US President George W. Bush described the killing as a "cowardly act" and telephoned Musharraf -- a crucial ally in the US-led "war on terror" against Islamic extremism -- to urge Pakistan to stay on the path of democracy.

However the elections now appear increasingly in doubt, with Pakistan's other leading opposition figure, Nawaz Sharif, announcing his party was pulling out.

"I demand that Musharraf quit power, without delay of a single day, to save Pakistan," the former premier told reporters.

Asian stock markets fell in early deals after heavy losses on Wall Street, partly triggered by concerns over Bhutto's death's impact on global stability.

Gold and oil prices also rose with crude futures climbing back towards the 100 dollars-per-barrel mark.

Bhutto was an outspoken critic of Al-Qaeda-linked Islamic extremists blamed for scores of bombings in Pakistan, and she had received death threats from militant groups.

She had also accused elements from the intelligence services of involvement in a suicide attack on her convoy in Karachi on October 18 as she returned from exile. She narrowly escaped, but the attack left 139 people dead.

Her father Zulfiqar Ali Bhutto, who was also prime minister and founded the Pakistan People's Party that she took over, was executed by the military in 1979 after being ousted from power.

Bhutto was expected to be buried next to him at around noon (0830 GMT) in the ancestral graveyard in the village of Garhi Khuda Bakhsh near Naudero, her spokesman Farhatullah Babar said.

Security was tight with thousands of party members and supporters expected to attend the ceremony.

Meanwhile, close aides released an email in which she accused Musharraf of deliberately failing to provide adequate security.

Her US spokesman Mark Siegel told CNN that Bhutto had asked authorities to provide protection including an escort and jamming devices against bombs, but she had not received them.

Musharraf, for his part, urged people to remain peaceful "so that the evil designs of terrorists can be defeated." All schools, businesses and banks were ordered to close down.

But mobs of protesters took to the streets, torching buildings, trucks and shops, blocking roads and uprooting rail tracks. Shots rang out in a number of cities.

In Jacobabad in the south, protesters set fire to shops belonging to family members of interim premier Mohammedmian Soomro.

Bhutto became the first elected female leader of a Muslim country when she took the helm in 1988. She was deposed in 1990 amid corruption allegations but was premier again between 1993 and 1996.

Educated at Oxford and Harvard, Bhutto's return here in October after eight years of self-exile brought hopes of power-sharing with Musharraf, who seized power in a coup in 1999, and an end to military rule.

The hopes were quickly shattered however, first by the Karachi bombing and then when Musharraf imposed emergency rule on November 3, lifting it only six weeks later.

US Secretary of State Condoleezza Rice called Bhutto's party successor and Bhtto's husband Asif Zardari by telephone to call for the January elections to go ahead, State Department spokesman Tom Casey said.

World leaders roundly condemned what neighbour India called an "abominable act." United Nations chief Ban Ki-moon described it as a "heinous crime," and the UN Security Council condemned the "terrorist suicide attack" after meeting in emergency session.