In Baghdad, the bodies of 24 men slain in ambushes were brought to a hospital.
A suicide car bomber also rammed his vehicle into an Iraqi army checkpoint, killing five soldiers and wounding two others in Kan'an, about 30 miles north of Baghdad, Iraqi Army Col. Ismael Ibrahim said. Two civilians were also wounded.
Security forces captured a reported key member of Abu-Musab al-Zarqawi's al-Qaeda in Iraq terrorist group who is accused of building and selling cars used by suicide bombers, the government said Tuesday.
Jassim Hazan Hamadi al-Bazi, also known as Abu Ahmed, was arrested June 7 and was part of an al-Qaida cell run by a man identified as Hussayn Ibrahim, the government said.
The spree of killings comes as lawmakers wrangle over how big a say Sunni Arab Muslims should have in drawing up a new constitution. The dispute threatens to further alienate Sunni Arabs, who fell from power after their patron, Saddam Hussein, was ousted and detained. Sunni Arabs account for most of the insurgents wreaking havoc across Iraq.
In Kirkuk, 180 miles north of Baghdad, a bomb killed 19 people, including retirees waiting for checks and child street vendors, outside the Rafidiyan Bank, said police Brig. Sarhad Qadir. Another 81 people were injured, he said.
The bomb exploded close to a pedestrian walkway crossing the road in front of the bank. Children and other vendors selling products from sugar to kitchen utensils on both the bridge and the road underneath were among those killed.
"I came here to get my wages and I brought my grandson with me who insisted on accompanying me," said Hussein Mohammed, a 70-year old retired employee of the Northern Oil Co., his head swathed in bandages.
"The bomb exploded as we queued outside the bank and we were injured and rushed to hospital." The child survived.
The pavement outside the bank was strewn with rubble and glass from the building, while several bodies lay beneath wreckage. At least two nearby cars were set ablaze.
Kirkuk is an ethnically mixed oil-rich city where insurgents have routinely launched deadly attacks apparently seeking to foment ethnic tension.
In Baghdad, the bodies of 24 men -- some beheaded -- were brought to a hospital, morgue official Ali Chijan said. The men had been killed in recent ambushes on convoys in western Iraq.
He said two batches of bodies were brought to Yarmouk Hospital late Monday.
Seventeen of the bodies believed to be all Iraqis were found near Khaldiyah, 75 miles west of Baghdad, Chijan said.
Some of the bodies had been decapitated and others had been shot in the head, said Dr. Mohammed Jawad.
The bodies might belong to men who have been missing since their convoy delivering supplies for the US military was ambushed near Khaldiyah on Thursday, Jawad said.
Two were identified as an Iraqi policeman and an interpreter, but it was not immediately clear who they worked for.
Chijan said the badly decomposed bodies of another seven men, including one Iraqi and six believed to be "Asians," were brought to the hospital after being killed in a convoy ambush several days ago. Most had been shot in the face.
The slain Iraqi was identified as Ahmed Adnan, according to his cousin, Hussein Ali.
He told The Associated Press his cousin worked for the US-owned American-Iraqi Solutions Group, a large company dealing in Iraqi reconstruction projects with its headquarters in Carson City, Nev.
The company later sent the AP a statement saying 11 of its employees were killed Sunday when one of its five-vehicle supply convoys was ambushed east of Ramadi, 70 miles west of Baghdad, by up to 20 heavily armed bandits firing from a highway overpass.
"The attackers used light and heavy machine guns as well as rocket-propelled grenades to disable three of the five vehicles," the statement said.
The last two vehicles in the convoy escaped the attack, which the company said was "believed to be the work of bandits operating in the Anbar region and is not thought to be a terrorist operation."
The highway linking Baghdad to Jordan in the west cuts through volatile Anbar province, a region notorious for kidnappings, ambushes and bombings.
In announcing the arrest of al-Bazi, the government said he built and sold remote-controlled bombs used in roadside attacks from an electronic repair shop in Balad, 50 miles north of Baghdad.
He sold the bombs for about $18,000 each "and was involved in building suicide vehicle" bombs and land mines that were used in Balad and Samarra, 60 miles north of Baghdad, the statement said.
Al-Qaeda in Iraq and other extremist Islamic groups have been blamed for many suicide car bombings, beheadings and attacks.
On Monday, new footage of a subdued-looking Saddam released by the Iraqi Special Tribunal on Monday showed the former dictator being quizzed by a judge -- apparently on Sunday -- about the killings of at least 50 Iraqis in a Shiite town.
Unlike Saddam's combative appearance at his arraignment on July 1, 2004 -- the last time he was seen on video -- the new images reveal a man who appears to be a shadow of his former self.
Saddam's fall from power is seen as a contributing factor to the insurgency, which is being fanned by Sunni Muslim extremists and Saddam loyalists.
(Associated Press writers Sameer N. Yacoub and Sinan Salaheddin in Baghdad and Yehia Barzanji in Kirkuk contributed to this report.)