RAMADI, Iraq — The orange-red glow of the tracer rounds burns bright in the dusk, forming a perfect cone over the heads of the Marines and Iraqi soldiers patrolling a dusty walled street.
As the rounds ricochet off the walls, the bullets fly like a shower of sparks. One hits the leg of an Iraqi soldier. Just a few feet ahead, an alleyway offers protection from the bullets and a chance to return fire.
In the alley, hidden behind a small shrub, lies an artillery shell with two protruding wires -- an improvised explosive device waiting for the patrol.
Insurgents in Ramadi, the capital of restive Al Anbar province, are using increasingly sophisticated tactics against U.S. and Iraqi forces. As in the rest of Iraq, the improvised explosive device, which the military calls the IED, is the most common and deadliest weapon. But after three years of fighting, insurgents here are combining roadside bombs with small-arms fire or rocket-propelled grenades to lethal effect.
"Darwin works every day for the insurgency," said a Marine intelligence officer, whose work with classified information prohibits him from speaking publicly. "The guys who are left know their business. The dumb ones are weeded out very quickly."
Here, fighters are increasingly operating in small units, with two men serving as spotters and others firing weapons or setting off bombs.
Marine officers say some of the insurgent teams coordinate their attacks with other groups of fighters, sometimes signaling to each other with pigeons.
When insurgents or their supporters spot an American patrol moving through the streets or a squad holed up in a house watching over a street, they release pigeons from rooftop coops. A flock of birds rising in the sky is a sign that Americans have been spotted.
In Ramadi, such coordinated attacks occur many times a day.
"Last year, when I got IEDed, I looked around for the triggerman," said Chief Warrant Officer Jonathan Rabert, an infantry weapons officer. "This year, I look for an ambush."
The Marines here, part of the 3rd Battalion, 8th Regiment, say they faced a far less sophisticated enemy last year when they operated around Fallouja and the Abu Ghraib prison.
"He never came out and fought us with complex attacks," said Lt. Col. Stephen Neary, the battalion commander. "Last year there was nothing complex. Here he likes to put things together."
