BAGHDAD -- A suicide bomber driving a tractor blew himself up yesterday close to the infamous Abu Ghraib prison, wounding four civilians in the third insurgent attack at an Iraqi prison in three days.
Lieutenant Colonel Guy Rudisill, a US military spokesman, said prison officials heard an explosion, but it wasn't close enough to cause any damage. The blast killed the tractor's driver and injured four Iraqis, police Lieutenant Akram al-Zubaeyee said.
Al Qaeda in Iraq said 10 of its fighters died in a separate assault on the prison Saturday, while the US military put the insurgents' casualties at one dead and about 50 wounded. Forty-four American soldiers and 13 prisoners were injured in the fighting, the latest in a series of large-scale attacks by insurgents in Iraq.
In an Internet posting, Al Qaeda in Iraq contended about 20 militants scaled the prison's walls and one of them reached a prison tower and yelled: ''God is great!" It said the 10 fighters killed included seven suicide bombers.
The statement, which appeared late Sunday, was impossible to verify independently, and it conflicted with the US account.
The US military denied anyone got inside the prison during Saturday's attack and said no inmates escaped. It said only one suicide bomber participated, while others fired assault rifles, mortars, and rocket-propelled grenades.
Rudisill said he didn't think any attackers were captured. He said the wounded insurgents either escaped on their own or were dragged away by other militants.
The military said the insurgents staged simultaneous assaults on multiple locations at the prison Saturday, focusing on two guard towers and then using a car bomb to try to penetrate a gate.
Combat helicopters helped push back the attack, which was the largest at Abu Ghraib since insurgents fired mortar rounds into the compound nearly a year ago, killing more than 20 detainees and injuring nearly 100.
The third attack near a jail occurred Friday, when prisoners at Iraq's largest detention facility protested the transfer of several detainees deemed ''unruly" by authorities, throwing rocks and setting tents on fire. The disturbance injured four guards and 12 detainees, the military said yesterday.
The Friday protest was at Camp Bucca, which holds about 6,000 prisoners, nearly two-thirds of all those in Iraq. It caused only minor injuries before being brought under control, authorities said.
Abu Ghraib was at the center of the prison-abuse scandal last year after photographs were publicized showing US soldiers humiliating Iraqi inmates, including having them pile naked in a human pyramid. The United States holds nearly 3,500 prisoners at Abu Ghraib and about 7,000 elsewhere in Iraq.
Some Iraqi lawmakers have called for the release of the prisoners at Abu Ghraib, and the National Assembly's newly elected speaker, Hajim al-Hassani, told Al-Jazeera television the topic will be among the first discussed by lawmakers.
''There are some problems regarding the security issue and troubles concerning Abu Ghraib detainees," he said.
President Bush called Hassani yesterday to congratulate him on becoming parliament speaker.
''The two leaders expressed confidence that democracy will succeed in Iraq," White House press secretary Scott McClellan said.
Iraq's interim prime minister, Iyad Allawi, also congratulated Hassani, saying his election was ''a hopeful sign as you begin the assembly's tasks, including laying down the constitution."
The selection of Hassani, a Sunni Arab, ended weeks of bickering and cleared the way for the formation of a government more than two months after Iraq's first free election in 50 years.
Legislators next meet tomorrow, when they plan to name Kurdish leader Jalal Talabani as Iraq's president.
In Washington yesterday, Bush said seeing Iraq through reconstruction to a stable and secure democracy is a worthy cause that the United States will press regardless of whether its coalition partners remain there.
''The fundamental question is: Is it worth it? And the answer is, 'Absolutely, it's worth it for a free Iraq to emerge,' " said Bush, standing alongside visiting President Viktor Yushchenko of Ukraine, who is pulling his country's 1,650 troops out of the country to fulfill a campaign promise.
Ukraine expects to complete its troop withdrawal by the fall.