Former Pakistani Prime Minister Benazir Bhutto appeared in public Sunday for the first time since a deadly bomb attack on her homecoming convoy, visiting hospitalized victims and vowing that the assassination attempt would not force her into hiding. Thursday's attack, which killed at least 136 people and injured more than 200, was one of the deadliest in Pakistan's turbulent history. "We have to modify our campaign to some extent because of the suicide bombings," Bhutto told a small group of journalists at her Karachi residence shortly after visiting bomb blast victims at a Karachi hospital. "We will continue to meet the public. We will not be deterred."

Bhutto called for an independent inquiry into the assassination attempt and asked again why streetlights were off when her convoy was inching its way through the darkness Thursday.

Bhutto also called on the international community for help in the investigation, and repeated her assertion that extremists had infiltrated the government and its security apparatus.

"The closet supporters of militants and al-Qaida are determined to stop the restoration of democracy because they see it as a threat to the structure of militancy they have put into place," Bhutto said.

Bhutto spent about 15 minutes at Karachi's Jinnah Hospital. She visited survivors and distributed money to them while vowing to fight for the rights of Pakistanis, according to Saimi Jamali, a senior doctor at the hospital.

"Prime Minister Benazir!" chanted hundreds of supporters outside as Bhutto, who was guarded by armed police, left the hospital for the Pakistan People's Party stronghold of Lyari.

Bowing her head in prayer, she then visited the tomb of a Sufi saint in Lyari.

The People's Party declared a national day of mourning Sunday for victims of the attack, in which a grenade explosion was followed by a suicide bomber who blew himself up with a device laden with shrapnel. Many of Bhutto's guards were killed in the attack.

Thousands gathered for the prayer service in Karachi. Some shouted chants for revenge.

Bhutto met with women for separate prayers, calling for mothers to fight against extremism.

"We want to establish such a society in which mothers must raise children who never carry weapons to kill innocent, poor and weak," she said.

Muslim cleric Mufti Feroz Uddin led prayer services in Karachi, pleading for calm.

Morgue officials said 75 of the bodies have been buried, while another 29 remained unclaimed. Another 15 were so badly disfigured that they were unidentifiable, according to Anwar Kazmi, an official at Karachi's main morgue.

Police continued to question three men in the blasts.

The men were linked to a vehicle that police believe was used by one of the attackers who threw a grenade at Bhutto's convoy, a senior investigator said on condition of anonymity, due to the situation's sensitivity.

Police detained the three late Saturday in the south of Punjab province and took them to Karachi, where the bombing occurred, for questioning.

The senior investigator said police believed the men, who have not been charged, hold crucial clues to the bombing.

Bhutto, who served twice as prime minister and is Pakistan's main opposition leader, left in 1999 to avoid arrest in corruption cases brought against her by the then-government of Nawaz Sharif, ousted by current President Gen. Pervez Musharraf in an October 1999 coup.

However, Bhutto has held talks with Musharraf in recent months to discuss how to share power after parliamentary elections due in January.

Authorities say the bombing against her convoy bore the hallmarks of a warlord and the al-Qaida terror network.

Bhutto blamed al-Qaida and Taliban militants for the assassination attempt - but also hinted that government or military officials could have been involved.

"I think we should stop playing blame games. The government provided the best possible security to her," Deputy Information Minister Tariq Azim told The Associated Press on Saturday.

The list of people who could have targeted the pro-Western leader is long.

Bhutto has blamed remnants of the regime of former military leader Gen. Zia ul-Haq, who hanged her father in 1979 after deposing him in a coup.

Islamic extremists could also be bent on stopping a female political leader from modernizing Pakistan.

Prime Minister Shaukat Aziz said the attack was unlikely to delay January's elections, but that the government would be alert for future attacks.

---_

Associated Press writers Ashraf Khan in Karachi and Munir Ahmad in Islamabad contributed to this report.