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.
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.
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. ( BBC )