KARACHI, PAKISTAN — Benazir Bhutto on Sunday mingled with the public for the first time since a bloody attack on her homecoming celebrations, seeking to signal that she would not be deterred from greeting supporters as her party commences its campaign for parliamentary elections.
But her visits to a Karachi hospital where many of those wounded in Friday's suicide bombing were being treated and to a Sufi Muslim shrine afterward for prayers were brief, unannounced and tightly controlled, in contrast to the carnival-like open-air procession that preceded the deadly attack.
U.S. Secretary of State Condoleezza Rice called the Western-backed former Pakistani prime minister Sunday to offer condolences for the more than 135 people killed and hundreds injured in the attack, Bhutto's party said.
Speaking to journalists at the headquarters of her Pakistan People's Party, Bhutto acknowledged that she and her supporters would have to "modify our campaign to some extent" because of the attack.
But she added: "We will continue to meet the public. We will not be deterred."
During her 15-minute stop at Karachi's Jinnah Hospital, Bhutto visited the bedsides of several men who were injured while acting as volunteer security around her convoy. Police and party faithful took the brunt of the powerful blast, which came as Bhutto's convoy was in the ninth hour of a trip from Karachi's airport to the city center. The convoy was moving at less than 1 mph because of the enormous crowds who gathered to greet Bhutto as she returned from eight years of self-imposed exile. Bhutto, who was inside her steel-reinforced vehicle at the time, escaped injury.
After the hospital visit, she offered prayers at a shrine in Karachi's impoverished Lyari neighborhood, a traditional party stronghold. As word of her appearance spread, a crowd gathered and chanted: "Prime Minister Benazir!"
There has been no claim of responsibility for the bombing, though at least one radical faction had issued threats against Bhutto before her return. Bhutto said at a news conference hours after the attack that she believed Islamic militants had carried out the suicide bombing, with the possible complicity of some former and present officials in the government of President Pervez Musharraf.
The government has vehemently denied any responsibility and said everything possible was done to protect Bhutto.
The former prime minister sharpened her rhetoric Sunday, however, decrying "closet supporters of militants and Al Qaeda . . . determined to stop the restoration of democracy because they see it as a threat to the structure of militancy they have put into place."
Aides to Musharraf, who are still engaged in power-sharing negotiations with Bhutto, have tried to avoid overt criticism of her. On Sunday, however, Interior Minister Aftab Khan Sherpao, the target of a suicide bombing in April, said that investigations of such attacks were painstaking affairs and that it was unrealistic to expect immediate results.
Bhutto said the government should enlist foreign help in carrying out the investigation.
"We want the government of Pakistan to seek assistance from the international community -- they have the anti-terrorism expertise to investigate attacks of this nature," she said.
U.S. officials declined to say whether the FBI or other investigators stationed in Pakistan had been asked to provide help.
The White House on Sunday declined to comment directly on Bhutto's visit to the hospital.
"As we said immediately following the attack, we strongly condemn this violence, mourn the loss of innocent life, and continue to stand in solidarity with the people of Pakistan as they fight extremists," said spokesman Rob Saliterman.
Several members of Congress, speaking on Sunday TV talk shows, expressed strong concerns about the ongoing violence.
"I think we should be very worried about what's happening in Pakistan," Rep. Peter Hoekstra (R-Mich.) said on CNN's "Late Edition." "Not that it means that it's on a path to an imminent collapse, but Pakistan is critical in us being successful in taking out and defeating radical Islamists and Al Qaeda."
Karachi on Sunday continued burying its dead. More than three dozen bodies remained unclaimed at the city's main morgue, some because they were so mangled that they were unidentifiable.
Many of those slain at the mass rally had traveled from distant parts of the country, and family members traveled to Karachi to search for their bodies after realizing their relatives were missing.
Times staff writer Alan C. Miller in Washington contributed to this report.