It could be a suicide bomber of Al-Qaida or Taliban who exploded himself in Pakistan during the homecoming of former Prime Minister Benazir Bhutto and killed at least 136 people, authorities said Friday, as forensic experts studied the severed head of the alleged bomber to try to determine his identity.
Click here to see photos of the terrorist act
The attack - one of the deadliest in Pakistan's history - bore the hallmarks of militants linked to pro-Taliban warlord Baitullah Mehsud and al-Qaida, according to Ghulam Muhammad Mohtarem, the top security official in Sindh province, where Karachi is located. He suggested that Bhutto's camp had gotten carried away celebrating her return after eight years in exile, and had not taken the need for security seriously.
"We were already fearing a strike from Mehsud and his local affiliates and this was conveyed to the (Bhutto's Pakistan's) People's Party but they got carried away by political exigencies instead of taking our concern seriously," Mohtarem said.
Bhutto survived unscathed, but the back-to-back explosions that went off near a bulletproof truck in which she was riding turned her jubuliant homecoming parade through the city streets into a scene of blood and carnage, ripping victims apart and hurling a fireball into the sky. The attack shattered the windows of her truck. She appeared dazed afterward and was escorted to her Karachi home.
President Gen. Pervez Musharraf, the nation's leader, said he was "deeply shocked" by the attack and "condemned this attack in the strongest possible words. He said this was a conspiracy against democracy," the state-run Associated Press of Pakistan said.
Musharraf appealed for calm, promised an exhaustive investigation and stiff punishment for those responsible, APP reported.
There was no claim of responsibility for the attack, which cast a pall over Bhutto's talks with President Gen. Pervez Musharraf and possible plans for a moderate, pro-U.S. alliance. Leaders of her Pakistan People's Party were meeting at her Karachi residence Friday, and Bhutto was expected to hold a news conference afterward.
Mohtarem said nuts and bolts and steel balls packed around the explosives had made the bombing so deadly. He said it was impossible to prevent more such attacks.
Officials at six hospitals in Karachi reported 136 dead and around 250 wounded.
Karachi police chief Azhar Farooqi said that 113 people died, including 20 policemen, and that 300 people were wounded. It was not immediately possible to reconcile the differing death tolls.
Police collected forensic evidence - picking up pieces of flesh and discarded shoes - from the site of the bombing. The truck was hoisted away using a crane. One side of the truck, including a big portrait of the former premier was splattered with blood and riddled with shrapnel holes.
Interior Minister Aftab Khan Sherpao said 18 police died in the attack, as two police vehicles on the left side of Bhutto's truck bore the brunt of the blast.
He said authorities had done everything possible to protect the huge gathering of Bhutto supporters marking her return, but noted that electronic jammers fitted to the police escort vehicles were ineffective against a manually detonated bomb.
On the eve of Bhutto's arrival, a provincial government official had cited intelligence reports that three suicide bombers linked to Mehsud were in Karachi. The local government had also warned Bhutto could be targeted by Taliban or al-Qaida.
Earlier this month, local media reports quoted Mehsud - probably the most prominent leader of Islamic militants destabilizing its northwestern border regions near Afghanistan - as vowing to greet Bhutto's return to Pakistan with suicide attacks.
Karachi, which lies in the far south of Pakistan but has been buffeted by militant attacks in recent years, was quiet Friday. Schools were closed and traffic was thin, with city residents wary of venturing out.
Unrest broke in two districts but did not appear serious. Hundreds of Bhutto supporters hurled stones at vehicles and shops during a funeral procession for two victims, forcing police to cordon off the area. Elsewhere, Bhutto supporters ordered shops to close and burned tires in the road.
Bhutto had flown home Thursday to lead her Pakistan People's Party in January parliamentary elections, drawing cheers from crowds that police put at 150,000.
The throngs reflected Bhutto's enduring political clout, but she has made enemies of Islamicmilitants bytaking a pro-U.S. line and negotiating a possible alliance with Musharraf.
It remained unclear what impact the attack could have on reconciliation efforts between the two rivals: whether it could stiffen their resolve to fight militancy together or strain already bad relations between Bhutto and the ruling party supporting Musharraf.
Bhutto's husband, Asif Ali Zardari, said on Dawn News television that he suspected that "elements sitting within the government" who would lose out if Bhutto returned to power were involved in the attack.
He didn't elaborate, though Bhutto has accused conservatives in the ruling Pakistan Muslim League-Q party and the security services of secretly supporting religious extremists.
But Musharraf's camp sounded conciliatory.
Presidential spokesman Rashid Qureshi said he doubted the attack would deflect Bhutto from her course.
"If someone thinks that by spreading this kind of terror they will stop the political process in Pakistan, I don't think that's correct, I don't think that will happen," Qureshi told the AP.
Musharraf believes that "all political forces need to combine to face this threat which is basically the major, major issue that faces Pakistan," he said.
Bhutto had brushed off militant threats, dismissing authorities' appeals for her to use a helicopter to travel into Karachi to reduce the risk.
"I am not scared. I am thinking of my mission," she had told reporters on the plane from Dubai.
On arrival, she told AP Television News she was fighting for democracy and to help this nuclear-armed country of 160 million people defeat the extremism that gave it the reputation as a hotbed of international terrorism.
"That's not the real image of Pakistan," she said.
Leaving the airport, Bhutto refused to use a bulletproof glass cubicle that had been built atop the truck taking her toward the tomb of Pakistan's founding father, Mohammed Ali Jinnah. An AP photographer who saw the cubicle of the wrecked truck said it appeared to have shrapnel holes from the bombing.
Her procession had been creeping toward the center of Karachi for 10 hours, as supporters thronged her truck, when a small explosion erupted near the front of the vehicle. That was quickly followed by a larger blast, destroying two escorting police vans.
Manzur Mughal, the Karachi police officer in charge of the investigation said detectives had established that the same young man who threw the grenade blew himself up 22 seconds later next to the truck.
The attacker's head was found nearby and taken to a forensic lab to try to identify him, Mughal told The Associated Press.
The former premier had just gone to a downstairs compartment in the truck for a rest when the blast occurred, said Christina Lamb, Bhutto's biographer.
"So she wasn't on top in the open like rest of us, so that just saved her," Lamb told Sky News.
In the aftermath, bodies lay motionless in the street among pools of blood, broken glass, tossed motorcycles and bits of clothing. Some of the injured were rushed on stretchers into a hospital, and others were carried by rescuers in their arms.
The United States, the United Nations, the European Union, Afghanistan and India were among those who condemned the attack.
"Extremists will not be allowed to stop Pakistanis from selecting their representatives through an open and democratic process," said Gordon Johndroe, foreign affairs spokesman for U.S. President George W. Bush.
Bhutto had paved her route back to Pakistan through negotiations with Musharraf, a longtime political rival despite their shared liberal values. Their talks yielded an amnesty covering the corruption charges that made Bhutto leave Pakistan.
Musharraf won re-election to the presidency in a controversial vote this month by lawmakers that is being challenged in the Supreme Court. If he is confirmed for a new five-year presidential term, Musharraf has promised to quit the military and restore civilian rule.
Bhutto plans to contest the parliamentary elections due in January, and has ambitions to win a third term as prime minister.
Railways Minister Sheikh Rashid Ahmed said that he has asked the government to make the election campaign short after consultation with political parties, amid concern that large gatherings could be vulnerable to attacks.