More than 140 people were killed and about 400 wounded in the suicide attack as hundreds of thousands gathered to cheer Bhutto hours just hours after she returned to the country.

Democracy 'undermined'

Khan said: "Everyone here knew there was going to be a huge crowd turning up to see her return after eight years in self-imposed exile. Everyone also knows that there has been a spate of suicide bombings in Pakistan lately."

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"Perhaps Bhutto should have listened to Musharraf and delayed her return to Pakistan until the volatile security situation was better"

ndur5, Irving, US

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Bhutto has condemned the bombing as an "attack on democracy", but the former cricketer said that the deal with Musharraf, which gave her amnesty from corruption charges, had undermined democracy.

"The sad thing is, she didn't need to do it. Musharraf was sinking and isolated. He was on the point of declaring a state of emergency. Just when it looked as if he had no lifelines left, Benazir came back and bailed him out," Khan said.

"Worse, by publicly siding with a dictator, she has deliberately sabotaged the democratic process."

Bhutto has also been criticised by her niece, Fatima Bhutto, who accused her of exposing the crowds to danger for her own "personal theatre".

The newspaper columnist and poet said of her aunt: "She insisted on this grand show, she bears a responsibility for these deaths and for these injuries."

Public appearance

But on Sunday about 100 supporters cheered the former prime minister as she made her first public appearance since the assassination attempt.

Surrounded by security guards carrying automatic weapons, Bhutto waved to supporters before getting into a four-wheel-drive vehicle at the entrance of Karachi's Jinnah hospital, where many of the badly wounded were taken after the blasts.

Although Bhutto has pledged to contest next January's parliamentary elections, the attack on her parade has cast doubt on her plans to tour the country to drum up support in the coming months.

Three men were being questioned by police on Sunday. A senior investigator told the Associated Press news agency that they were linked to a vehicle that police believe was used by one of the attackers, who threw a grenade at the convoy.

Police detained the them in southern Punjab province and brought them to Karachi for questioning.