A suicide bomber driving an explosives-packed vehicle rammed his way into a barricaded police compound Thursday and killed 20 police officers in the second major deadly blast in Iraq this week.
Iraqi officials have been scrambling to show they're in control of security in the wake of Osama bin Laden's death on Monday, but the uptick of bombings suggests that al-Qaida-linked groups in Iraq remain a threat despite the death of their ideological patron.
There was no immediate claim of responsibility for this bombing or for another on Tuesday that killed nine people in a Shiite neighborhood in Baghdad. But the types of targets _ Iraqi security forces and Shiite Muslims _ indicate al-Qaida in Iraq's involvement.
"The attack bears the hallmark of al-Qaida which is renewing its efforts to destabilize the country," said a member of the region's provincial council, Hamid al-Milli.
The blast in the mainly Shiite city of Hillah, about 60 miles (95 kilometers) south of the capital Baghdad also underscores Iraq's fragile security at a time when U.S. forces are preparing to leave the country.
Violence in Iraq has dropped dramatically since just a few years ago, and Iraqi forces have firmly taken over security responsibilities from American troops. But many Iraqis and U.S. officials worry question whether the departure of the roughly 46,000 American soldiers still here will leave their country more vulnerable to violence.
Al-Milli said 20 policemen were killed and 40 more were wounded in the Hillah bombing. He said the car was believed to have been loaded with about 330 pounds (150 kilograms) of explosives. The attacker sped toward the police building and the guards did not have a chance to shoot and stop him, he said.
The suicide bomber plowed his way into a metal barrier designed to keep vehicles out of the police compound, leaving behind a crater a meter (yard) deep and three meters (yards) wide, said a police official in Hillah.
The reception building and a security tower near the entrance were leveled, and pieces of the damaged vehicles were flung around the compound.
The police officers were assembled for their morning shift change when the outgoing officers hand over equipment and weapons to the day shift, said the police official. About 60 or 70 policemen would have been in attendance, he said.
AP television footage showed ambulances and police vehicles with blaring sirens racing to and from the blast sight. A bulldozer moved debris from the scene, where twisted metal, spots of blood and piles of bricks and rubble lay. Emergency teams lifted bricks and iron bars from the debris, while shards of glass littered the site.
The fact that the bomber was able to wipe out so many policemen in one blast immediately raised questions about security at the building.
The head of the Babil Provincial Council, Kadim Tuman, said he was holding officials at the building and at the central government accountable.
"This building was not well fortified and the changing of policemen's shifts was exposed to the enemy," he said. The central government had also failed to provide extra police and explosive detection equipment, he said.
Hillah's proximity to a mainly Sunni area at one time referred to as the Triangle of Death has made Hillah a frequent target of Sunni extremists. In 2005, a suicide car bombing targeted at security recruits killed 125 people in the city. Last year, 45 people were killed outside a textile factory when two parked car bombs exploded.
Iraqi officials said in the immediate wake of bin Laden's death that they were beefing up security around the country amid fears that insurgent groups would try to carry out strikes to demonstrate their continued strength despite the al-Qaida leader's killing.
Iraqi security forces have taken steps to show they're in control. On Wednesday, Iraqi security officials showed confessions of what they said were al-Qaida members who had killed a journalist from a Shiite TV station. On Thursday, the Interior Ministry displayed a cache of rockets and other munitions that had been seized this week.
The head of the ministry's intelligence department, Maj. Gen. Mahdi Hadi al-Fikkaiki, defended the government's ability to protect Iraq, and said his department had foiled many terror attacks before they'd been carried out. But he acknowledged that there was no way to make the country 100 percent safe.
Fawaz A. Gerges, a London-based expert on al-Qaida, said offshoots like al-Qaida in Iraq may try to carry out terror attacks as a way to show the American government and local authorities that they still exist and remain dangerous.
"I think Iraqis should brace themselves for more insidious attacks in the next few days and the next few weeks," he said.
Associated Press writers Bushra Juhi and Sinan Salaheddin in Baghdad and Sameer N. Yacoub in Amman, Jordan contributed to this report.