Supporters of slain opposition leader Benazir Bhutto lay flowers in front of their leader's portrait during a ceremony Saturday in Rawalpindi, Pakistan. Islamic militants said Saturday they had no link to Bhutto's assassination, dismissing government claims that a leader of pro-Taliban forces in Pakistan orchestrated the suicide attack on the opposition leader.

Islamabad, Pakistan ? Pakistan rejected an outside investigation into the assassination of Benazir Bhutto on Saturday, despite controversy over the circumstances of her death and three days of paralyzing turmoil.

The Islamic militant group blamed by officials for the attack denied any links to the killing on Saturday, and Bhutto’s aides accused the government of a cover-up.

The disputes were sure to further inflame unrest that has killed 44 people over three days and threatened to derail Jan. 8 parliamentary elections meant to restore democracy in this nuclear armed nation, a key ally against Islamic extremism.

The growing questions about Bhutto’s assassination have led to calls for an international, independent investigation. While the government dismissed that idea, U.S. officials said Pakistan was quietly consulting with other countries about the conduct of the probe, suggesting the country wants to ensure its findings are seen as credible.

Interior Ministry spokesman Javed Iqbal Cheema defended the government’s ability to carry out its investigation. He said an independent judicial probe should be completed within seven days of the appointment of its presiding judge.

“This is not an ordinary criminal matter in which we require assistance of the international community. I think we are capable of handling it,” he said.

Bhutto died Thursday evening when a suicide attacker shot at her and then blew himself up as she waved to supporters from the sunroof of her armored vehicle outside a campaign rally.

Her Pakistan People’s Party called a meeting today expected to choose a new leader, decide whether to participate in the Jan. 8 elections and hear her last will and testament.

If the party pulls out, it would destroy the credibility of the poll, already being boycotted by rival opposition leader Nawaz Sharif. The U.S. has pressured President Pervez Musharraf, who seized power in a coup eight years ago, to push ahead with the election to promote stability.

Democratic presidential candidate Hillary Rodham Clinton said Friday that an international probe into Bhutto’s death was vital because there was “no reason to trust the Pakistani government.” Others called for a U.N. investigation.

White House spokesman Tony Fratto said Pakistan had not officially requested U.S. help.

“It’s a responsibility of the government of Pakistan to ensure that the investigation is thorough. If Pakistani authorities ask for assistance we would review the request,” he said.

A senior U.S. official, however, said Pakistan was already “discussing with other governments as to how best the investigation can be handled.”

With the United States, the discussions “are about what we can offer and what the Pakistanis want. Having some help to make sure international questions are answered is definitely an option,” the official said, speaking on condition of anonymity because no agreement had yet come from the discussions.

There was no immediate confirmation from Pakistani officials.

British Foreign Secretary David Miliband offered his country’s assistance. “Obviously it’s very important that a full investigation does take place, and has the confidence of all concerned,” he said.

The government blamed the attack on Baitullah Mehsud, head of the Tehrik-i-Taliban, a newly formed coalition of Islamic militants along the Afghan border believed to be linked to al-Qaida and committed to waging holy war against the government.