Karachi, Pakistan ? Somber but defiant, former Prime Minister Benazir Bhutto on Friday said the massive attack that missed her but killed up to 140 others on Thursday would not deter her from seeking public office, even though she continued to receive credible reports of plots against her.

“We are prepared to risk our lives and we are prepared to risk our liberty, but we are not prepared to surrender our great nation to the militants,” Bhutto told journalists who packed into her compound in this coastal city. She vowed to press ahead with her campaign to return to the prime ministership and restore democratic, civilian rule to Pakistan.

In her first public comments since her narrow escape Thursday night, Bhutto said she had previously passed along information to the government warning that suicide squads would be hunting her as she returned to Pakistan after eight years in exile. She also said that she had sent the president, Gen. Pervez Musharraf, a letter on Tuesday in which she named three people who she said are plotting to kill her.

She declined to publicly name the three. But she said she has been told specifically of a new plot by would-be assassins to disguise themselves as police officers and try to kill her in Karachi or in her home town of Larkana.

Bhutto has been targeted in the past by Islamic extremist groups because of her secular attitudes and ties to the West. But she has also said retired and active-duty members of the military are conspiring against her. Her party has long opposed the military’s role in government.

Deputy Information Minister Tariq Azim Khan denied that anyone from the military was involved in the attack and said that the strike showed “all the hallmarks” of al-Qaida and the Taliban.

Khan said that the government had warned Bhutto about the threats on her life, asking her to delay her homecoming, and that she recklessly chose not only to return but to take part in a snail’s-pace procession through Kararchi that left her vulnerable.

“She might have underestimated the threat that was being posed,” Khan said.

Musharraf has ordered officials to conduct an inquiry into the attack within 48 hours and report to him with the names of the organizers.

No one has asserted responsibility for the attack.