More than 600 fighters loyal to Shiite cleric Moqtada al-Sadr and 16 of their leaders have been captured by security forces in a crackdown on the cleric's militia, the US military said Tuesday.
"There are currently over 600 illegal Jaish al-Mahdi (JAM) militia in detention awaiting prosecution from the government of Iraq," a military statement said.
It said Iraqi and US forces had also detained "16 high-level JAM militiamen and killed one JAM commander" in a series of operations.
The military added that five of the high-level individuals detained are from Sadr City, Baghdad's impoverished Shiite bastion loyal to Sadr.
Combined Iraqi and US forces have carried out 52 operations in the past 45 days focused on the JAM, or Mahdi Army, and 42 operations targeting Sunni extremists, the statement said.
The recent detentions are in addition to six other Mahdi militia leaders who have been detained since the beginning of October.
"The detainees are responsible for attacks against the government of Iraq, Iraqi citizens and coalition forces," the military said.
"Criminal activities by these individuals propagated instability within Iraq and their removal from the social structure is a critical start to providing the Iraqi populace with a safe and stable environment."
The operations against the Sunni extremists resulted in the capture of 33 cell leaders in Baghdad, the statement said.
These detainees are "responsible for foreign fighter facilitation, car bomb facilitation, and propaganda operations," the military statement said.
Iraqi and US forces, reinforced by up to 10 brigades, are preparing a broad offensive against insurgent and militia groups focused on Baghdad in an attempt to quell sectarian violence that killed tens of thousands of Iraqis last year.
The US military has regularly charged that Sadr's Mahdi Army is heavily involved in sectarian killing of Sunni Arabs in Baghdad and other regions of the country.
The latest quarterly Pentagon report, released last month, said Sadr's milita was the largest threat to security and "has replaced Al-Qaeda in Iraq as the most dangerous accelerant of potentially self-sustaining sectarian violence in Iraq."
Sadr's Iranian-backed militia is believed to have up to 60,000 fighters, and is blamed for much of the violence against minority Sunnis.
US and Iraqi authorities aim to track down these fighters as part of a new Baghdad security plan announced by US President George W. Bush earlier this month.
The head of the US-led coalition forces in Iraq, General George Casey, recently said that "all militias will be targeted" as part of the new plan.
On Friday, security forces captured a top Sadr aide from Baghdad, Sheikh Abdul Hadi al-Darraji, who is the Baghdad spokesman for the group.
Darraji was detained in an early morning raid along with four others from a Shiite religious site near Sadr City.
Sadr and the Mahdi Army are known for their anti-American stance.
Before joining Iraq's political process, Sadr led two bloody rebellions against US forces in April and August 2004, a year after the US-led invasion to topple Saddam Hussein.
Sadr's fighters suffered heavy casualties in battles fought in the Shiite holy city of Najaf.
Two US troops killed in Iraq
Meanwhile, two more US troops have been killed in Iraq, south of Baghdad and in the western Anbar province, raising the military's losses to 49 in January, the military said on Tuesday.
A marine "died Sunday from wounds sustained due to enemy action" during an operation south of Baghdad, and a soldier died on Monday in similar circumstances in the restive Anbar province, a military statement said.
Saturday was one of the deadliest days since the March 2003 invasion, with 25 US service members killed across the war-torn country.
The latest fatalities brought US losses since the invasion to 3,055, according to a count based on Pentagon figures.
Top Republicans move against Bush's Iraq troop hike plan
Top Republican senators Monday assailed President George W. Bush's plan to increase US troops in Iraq, adding critical strength to the movement in Congress against his new war plan.
In a rising revolt in Bush's own party, senior Republican Senator John Warner and colleagues proposed a resolution calling on Bush to find alternatives to his plan, announced January 10, to send 21,500 more US troops to Iraq in a last-ditch effort to restore security.
In a press conference together with Republican Senators Susan Collins and Norm Coleman, Warner said the resolution aimed at registering "genuine concerns" in the Congress about Bush's plan.
"It is clear that the United States' strategy and operations in Iraq can only be sustained and achieved with support from the American people and with a level of bipartisanship in Congress," Warner, an influential member of the powerful Senate Armed Services Committee, said.
"The purpose of this resolution is not to cut our forces at the current level or to set any timetables for withdrawal but, rather, to express the genuine, and I repeat, the genuine concerns of a number of senators from both parties about the president's plan," he said.
The non-binding resolution, one of several proposed challenging Bush's war plan but the first offered by such senior Republicans, reads: "The Senate disagrees with the plan to augment our forces by 21,500 and urges the president instead to consider all options and alternatives for achieving the strategic goals set forth below with reduced force levels than proposed."
Warner's announcement came a day before Bush is to defend the highly unpopular strategy in his annual State of the Union speech to Congress.
In also comes as Democrats in the Senate -- with the support of Republican Senator Chuck Hagel --are readying a more strongly-worded, also non-binding resolution that says the troop increase is not in the national interest of the United States.
The Democratic resolution heads for debate Wednesday in the Senate Committee on Foreign Relations.
Warner's resolution stresses that it is not aimed at contravening Bush's power as the US Commander in Chief, but insists that Congressional and popular support is key to sustaining the US effort in Iraq.
It says the US strategy should focus on conducting counter-terrorism operations in Iraq and training and equipping Iraqi forces to assume security responsibilities.
While Bush's plan also includes those point, its key focus is to increase US troop levels in an attempt to reestablish security in Baghdad and Al-Anbar provinces before handing security duties over to the Iraqis.
With already more than 3,000 new troops having arrived in Iraq over the weekend under the new plan -- in addition to more than 130,000 already in the country -- Bush has remained determined to push ahead with the new approach.
"What matters is what happens on the ground. That would be the best way to show the American people that the strategy, the new strategy I've outlined, will work," Bush told USA Today in an interview published Monday.
White House spokesman Tony Snow echoed the point to reporters Monday: "George W. Bush as a president is not somebody who is going to cease to be bold because right now people are concerned about the progress of the war."
Democrats, who took control of Congress in November elections amid voter anger over the war, are using their newfound power to challenge the president on Iraq.
They have insisted that Bush will not get "a blank check" as they consider a raft of proposals, ranging from a resolution rejecting his troop increase, to bills capping US forces at the existing level or even cutting war funds altogether.