From Reuters via The Australian :

US Marines had detained what they believe is a senior commander in the Sunni Muslim insurgency in Iraq’s western Anbar province, the US military said today.

Marines detained six suspected guerillas yesterday in Haqlaniya in Anbar, a province which includes the insurgent strongholds of Fallujah and Ramadi, a military statement said.

“One of the six detainees is believed to be a high-ranking cell leader of anti-Iraqi forces operating in and around the Al Anbar province,” it added, giving no further details.

From the New York Times :

For a correspondent who has covered a half dozen armed conflicts, including the war in Iraq since its start in March 2003, the fighting seen while traveling with a frontline unit in Falluja was a qualitatively different experience, a leap into a different kind of battle.
[…]
On one particularly grim night, a group of marines from Bravo Company’s First Platoon turned a corner in the darkness and headed up an alley. As they did so, they came across men dressed in uniforms worn by the Iraqi National Guard. The uniforms were so perfect that they even carried pieces of red tape and white, the signal agreed upon to assure American soldiers that any Iraqis dressed that way would be friendly; the others could be killed.

The marines, spotting the red and white tape, waved, and the men in Iraqi uniforms opened fire. One American, Corporal Anderson, died instantly. One of the wounded men, Pfc. Andrew Russell, lay in the road, screaming from a nearly severed leg.

A group of marines ran forward into the gunfire to pull their comrades out. But the ambush, and the enemy flares and gunfire that followed, rattled the men of Bravo Company more than any event. In the darkness, the men began to argue. Others stood around in the road. As the platoon’s leader, Lt. Andy Eckert, struggled to take charge, the Third Platoon seemed on the brink of panic.

“Everybody was scared,” Lieutenant Eckert said afterward. “If the leader can’t hold, then the unit can’t hold together.”

The unit did hold, but only after the intervention of Bravo Company’s commanding officer, Capt. Read Omohundro.

Time and again through the week, Captain Omohundro kept his men from folding, if not by his resolute manner then by his calmness under fire. In the first 16 hours of battle, when the combat was continuous and the threat of death ever present, Captain Omohundro never flinched, moving his men through the warrens and back alleys of Falluja with an uncanny sense of space and time, sensing the enemy, sensing the location of his men, even in the darkness, entirely self-possessed.

“Damn it, get moving,” Captain Omohundro said, and his men, looking relieved that they had been given direction amid the anarchy, were only too happy to oblige.

A little later, Captain Omohundro, a 34-year-old Texan, allowed that the strain of the battle had weighed on him, but he said that he had long ago trained himself to keep any self-doubt hidden from view.

“It’s not like I don’t feel it,” Captain Omohundro said. “But if I were to show it, the whole thing would come apart.”

For Expert Opinion on how the US Marine Corps “re-wrote the book” on MOUT (Miliatary Operations in Urban Terrain) see these articles in the Post-Gazette,