Former Pakistani Prime Minister Benazir Bhutto says she knew she was a target for assassination when she returned home to Karachi this week, but that she decided not to allow such threats to change her plans.

Speaking to reporters Friday at her family home in Karachi, Ms. Bhutto said a foreign government had informed her that four assassination teams, including suicide squads from the Taliban and al-Qaida, were planning attacks against her.

Deadly explosions that ripped through a crowd greeting Ms. Bhutto Thursday killed at least 136 people and wounded hundreds of others. While mourning the casualties, the former prime minister said she cannot let such attacks set back her political efforts in Pakistan.

The bombs were not an attack on her, Ms. Bhutto said, but on democracy, and on Pakistan's integrity. She says she is not prepared to surrender Pakistan to militants.

A top Taliban commander has denied any involvement in Thursday's carnage, and no other group has claimed responsibility for the attack, which has been strongly condemned around the world. President Pervez Musharraf also has denounced the attack, and he is promising a thorough investigation.

Pakistani Interior Minister Aftab Sherpao says officials urged Ms. Bhutto not to drive through Karachi's clogged streets, for security reasons, and advised her to fly into the center of the southern port city by helicopter. Sherpao said the leadership of Ms. Bhutto's Pakistan People's Party refused to agree to a flight, so they bear some responsibility for the attack.

Some information for this report provided by AP and Reuters.