Former Pakistani PM Benazir Bhutto has accused former army officials of being behind twin bomb attacks on her convoy that killed more than 130 people.
She said she had been warned that she would be targeted by four groups and had earlier told the government the names of the masterminds of the blasts.
Ms Bhutto condemned the "dastardly and cowardly" attack in Karachi and said Pakistan faced a battle for democracy.
But she stressed that she was not blaming the government.
Ms Bhutto, who had returned to the country after eight years of self-imposed exile, was unhurt.
'Attack on democracy'
In her first public statement since the blast, she told a news conference that before the bombing, shots had been fired at her vehicle to stop it. It was unclear whether the driver had been disabled by this gunfire, she said.
Ms Bhutto also called for an inquiry into why the street lights along her route had been switched off, saying security guards would have spotted suicide bombers if the street lights had been on.
She said she had been warned that Taleban, al-Qaeda and an unspecified group in Karachi were planning attacks on her, but she blamed "certain individuals who abuse their positions" - without specifying what these positions were - for orchestrating the blasts.
"For me, the attack was not on an individual, the attack was on what I represent - it was an attack on democracy, an attack on the very unity and integrity of Pakistan," she said.
Ms Bhutto said those who had died in the attack - including 50 of her security guards - had made the "ultimate sacrifice" for democracy.
Questions and accusations
The BBC's Damian Grammaticas in Karachi says Ms Bhutto is clearly attempting to portray herself as a brave fighter for democracy.
But he adds that there are bound to be questions about why, if she had been warned of a suicide bomb attack, she authorised such a slow public procession from the airport attended by hundreds of thousands of supporters.
Earlier, in an interview published on the website of Paris-Match magazine, she accused former officials in the government of late military ruler Mohammed Zia ul-Haq of masterminding the attack against her.
"I know exactly who wants to kill me. It is dignitaries of the former regime of General Zia who are today behind the extremism and the fanaticism," she said.
Zia overthrew Ms Bhutto's father, Prime Minister Zulfikar Ali Bhutto in 1977, and had him hanged two years later. The military ruler died in mysterious circumstances in a plane crash in 1988.
Subsequent elections saw Ms Bhutto elected for the first of two stints as prime minister.
Scenes of chaos
The twin blasts in Karachi took place after midnight local time, as Ms Bhutto and her entourage were moving slowly through a crowd of hundreds of thousands of supporters.
Hundreds of people were injured and there were scenes of chaos, with the streets littered with bodies and body parts.
Most of the dead were members of Ms Bhutto's Pakistan People's Party
Authorities say the first blast was caused by a hand grenade and the second was a suicide blast, but the exact sequence of events remains unclear.
It was estimated that the suicide bomber had had 15-20kg (33-44lb) of explosives strapped to his body, senior police official Manzoor Mughal told Reuters news agency.
No group has said it carried out the attack, police say they are investigating whether the attack has links to tribal regions bordering Afghanistan, which are deep wells of support for al-Qaeda and the Taleban.
Ms Bhutto's return followed a deal with Pakistan's military ruler, President Pervez Musharraf. The two could end up sharing power after elections in January.
On both occasions that Ms Bhutto served as prime minister, her government was prematurely dismissed by the president of the day under special powers.
She left Pakistan in April 1999, shortly before Gen Musharraf seized power in a coup, and two years after her husband was jailed and a series of corruption charges were brought against her. She denies the charges.
Mrs Bhutto was travelling from the airport to the Quaid e Azam mausoleum where she was due to address a rally
Her slow moving convoy was attacked near the recently built Karsaz bridge on the Sharah e Faisal, the main road into the city centre
Following the blasts, scores of wounded were taken to the nearby Jinnah medical centre
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