The insurgent was arrested Thursday by soldiers of the 502nd Infantry Regiment, 101st Airborne Division during a cordon and search operation in Baghdad, a military statement said. It did not identify the insurgent, but described him as a "key terrorists cell leader."
He "is directly linked" to the July 17 attack on a local market in Mahmoudiya, about 20 miles south of Baghdad, the statement said.
In the Mahmoudiya attack, suspected Sunni gunmen opened fire on shoppers and vendors in a market, killing at least 51 people and injuring more than 70. Most of the dead were Shiites, victims of the sectarian violence sweeping Iraq.
"This is the third top member of this violent and elusive terrorist cell we have detained in recent weeks," Col. Todd Ebel, commander of the 2nd Brigade, 101st Airborne Division, was quoted as saying in the statement.
On Friday, U.S. soldiers arrested 60 men from a Sunni neighborhood in Baghdad, known to be a stronghold of insurgents. They included members of an al Qaeda-affiliated cell that "specializes in bomb making" and carried out car bomb attacks in the capital, the U.S. command said.
About 1,000 people are being killed every month in the Baghdad area alone in the Sunni-Shiite sectarian violence, which has become a new security challenge to U.S. and Iraqi military trying to control a three-year-old insurgency by loyalists of Saddam Hussein.
In other developments:
The new push by U.S. and Iraqi forces to reverse a rising tide of violence in Baghdad will target four violent "hotspots" in the city, the American general in charge of the plan said Saturday.
Those parts of the city have experienced frequent kidnappings, suicide bombings and revenge killings by Shiites and Sunnis.
More than 7,000 U.S. reinforcements – almost twice the number originally expected – are now going block by block through the Iraqi capital's Dora neighborhood, reports CBS News correspondent Mark Strassmann, who was the only television reporter to witness the searches.
Maj. Gen. James Thurman, commander of the Army's 4th Infantry Division, said the renewed push for stability began Aug. 7 in Dora, a notoriously violent part of the city. He said sweeps of Dora neighborhoods had captured 179 people thus far and killed 25 "terrorists."
But, Dora is a just about the last place in Baghdad to feel safe, Strassmann reports. There were 20 murders in the neighborhood in one day.
Still Thurman – who is called the "Thurminator" by his troops – is confident.
"I think this is the definitive moment of this campaign," Thurman told Strassmann.
The other three targeted districts are Mansour and the Ghazaliyah-Shula areas of western Baghdad and the Azamiyah area in the northeast, he said, adding that the goal is to quell the violence and restore ordinary Iraqis' confidence in their government's ability to provide security and basic services.
"I'm confident, based on what I'm seeing right now, that we've got a positive trend here happening," Thurman said in an interview after joining Gen. Peter Pace, chairman of the Joint Chiefs of Staff, in a question-and-answer session with several dozen soldiers, sailors and airmen at Camp Liberty.
"We've got four major hotspots where we've had a lot of sectarian killings," Thurman said. "And we've got a plan that will zero in on reducing the number of murders, kidnappings, assassinations and car bombs."
Pace, who arrived Saturday from Washington, met with Thurman and other senior American commanders and addressed the troops at Camp Liberty to thank them for their service.
A few of the soldiers in his audience were with the Alaska-based 172nd Stryker Brigade, whose one-year tour of duty in Iraq was extended by four months recently in order to add another 3,500 soldiers to Thurman's force in the capital. Thurman said he has received another 2,000 extra troops from other units.
Thurman said he now has 32,444 U.S. troops in Baghdad and areas south of the capital, as well as 32,554 Iraqi forces. Of the U.S. total, about 13,500 are in Baghdad proper, he said.