Pakistani investigators reconstructed a mangled human head on Friday hoping to identify the man suspected of killing former Pakistan prime minister Benazir Bhutto in a suicide attack.
Bhutto was killed in a gun and bomb attack as she left an election rally in the city of Rawalpindi on Thursday, plunging Pakistan into one of the most serious crises in its 60-year history.
''We have retrieved a head and it has been reconstructed. We also found fingers and we're carrying out DNA tests to make a comparison between the head and fingers,'' said Saud Aziz, police chief of Rawalpindi.
A man shot at Bhutto as she waved to her supporters from the sun-roof of her bullet-proof car. He then blew himself up.
Bhutto was killed by gunshots to the head and neck, a security official said. The blast killed 17 other people.
Moments after the blast, a Reuters reporter saw a portion of a head, including a blackened ear and half a face on the road. Police cordoned it off.
Aziz said samples had been taken from the site for testing to determine what type of explosive had been used.
While Aziz declined to speculate on who might have been behind Bhutto's murder, it bore all the hallmarks of strikes by Islamist militants fighting to destabilise the government of US ally President Pervez Musharraf.
Musharraf had survived two bomb attacks in 2003. A suicide bomber tried to kill former prime minister Shaukat Aziz in 2004 and outgoing Interior Minister Aftab Ahmed Khan Sherpao survived two suicide bomb attacks this year that killed nearly 70 people.
Militants were believed responsible for at least five bomb attacks on security force personnel in recent months in Rawalpindi, where the Pakistani military has its headquarters, and numerous other attacks elsewhere this year.
In a brief address to the nation, Musharraf said that Bhutto was a victim of the terrorists the government had been battling.
Bhutto survived a suicide attack in October, hours after she returned form eight years of self-imposed exile, in the city of Karachi. The attack killed about 165 people.
Bhutto had spoken of al Qaeda plots to kill her. While she commanded a devoted following in some quarters, she had enemies apart from Islamist militants.
After the attack on her homecoming procession in Karachi, she made vague references to some Musharraf allies and the head of a main security agency who, she said, were out to get her.
But al Qaeda was the chief suspect in the murder, standing to gain by preserving its remote stronghold, undermining Musharraf and destabilising Pakistan, US government and private analysts said.
''There are a number of extremist groups within Pakistan that could have carried out the attack ... Al Qaeda has got to be one of the groups at the top of this list,'' a US official said.
A private analyst said militant supporters in Pakistan's security services might have also played a role, but it was unlikely that Musharraf himself was involved.