First major attack since emergency was lifted kills at least 10 military recruits.
Two days earlier, a suicide bomber killed nearly 50 worshippers in a mosque during Eid al-Adha prayers in the northwestern town of Charsadda.
Bhutto said Pervez Musharraf, the Pakistan president, had spoken of the need to reform religious schools, or madrasas, but had done nothing.
She said she respected genuine religious schools.
“Then there are the political madrasas, the political madrasas that teach their pupils how to make bombs, how to use rifles and how to kill women, children and the elderly,” she said.
“Who are they who tell children to carry out bombing on Eid al-Adha?”
During her public appearances on Sunday, Bhutto accused the government of failing to crush the pro-Taliban uprising, saying: “Militants gained power and the government’s legitimacy weakened.
“In our north, the flag of Pakistan is being lowered and the flag of extremism is being raised.”
She also called for mass protests if pro-Musharraf parties win the election.
“The government has created a rogue force. They have hired goons who will be deployed at polling stations in police uniform, which will be a source of vote rigging,” Bhutto said.
The vote for provincial parliaments and a national assembly from which a prime minister and a government will be drawn is a three-way race between Bhutto, Nawaz Sharif, another former prime minister, and the party that ruled under Musharraf.
Analysts expect a hung parliament, which would likely mean two of the three main parties having to forge an alliance.
To add to the Musharraf government’s discomfiture, the New York Times has reported that more than $5bn in US aid often never reached the military units it was intended for to fight al-Qaeda and the Taliban.
The cash was instead diverted to other programmes, the daily said on Monday.
Much of the money meant to reimburse frontline Pakistani units was channelled to weapons systems aimed at India and to pay inflated Pakistani reimbursement claims for fuel, ammunition and other costs, unnamed US government and military officials said.
A US official visiting the Pakistan-Afghanistan border recounted finding members of Pakistan’s frontier corps “standing there in the snow in sandals”.
Several soldiers were wearing World War I-era pith helmets and had battered Kalashnikov rifles with only 10 rounds of ammunition each, the official said.