The U.S. military in Iraq is increasingly concerned about roadside bombs that are taking a greater toll on U.S. troops than at any time since dictator Saddam Hussein was toppled in April, 2003. Iraqi insurgents are assembling bigger bombs and finding better ways to hide them, often foiling American efforts to counter their effectiveness.
At an American Army base in Mahmudiyah, south of Baghdad, hundreds of grieving soldiers gathered recently to pay their last respects to two comrades killed in action.
The Army National Guard soldiers, who died earlier this month, joined a growing list of U.S. troops killed by roadside bombs since the fall of Saddam Hussein in April, 2003.
According to statistics assembled by the Internet Web site, Iraq Coalition Casualty Count, a total of 550 American military personnel in Iraq have died in the past two-and-one-half years from injuries caused by what the military calls improvised explosive devices, known as IEDs.
In a worrying sign of the increasing deadliness of IEDs, 110 Americans were killed between May and July of this year. Last month, the toll reached an all-time monthly high of 40. This month, IEDs have killed more than 30.
Roadside bombs now account for an estimated 70 percent of all combat deaths among U.S. troops. In 2004, it was about 26 percent.
Even battle-hardened soldiers and Marines acknowledge that climbing into their Humvee vehicles to conduct daily patrols often causes feelings of fear and dread. Army Staff Sergeant Danny Machiavelo just spent the past six months working as a gunner and driver in a unit, which patrolled Baghdad's once notoriously dangerous Airport Road.
"Yea, you get butterflies," he admitted. "You are thinking about what can go wrong, not what can go right. If we think about what can go right, there is no need for anxiety. But we do not know what is going to happen. Every day is a different story."
U.S. commanders say one of the reasons why IEDs have been so effective a weapon is the adept way in which insurgents conceal the roadside bombs.
Most IEDs are made of artillery or mortar shells, fitted with a remote detonator. A typical bomb is small enough that it can be hidden among ordinary roadside trash. IEDs have been found wrapped in burlap sacks, plastic bags, aluminum cans, pieces of clothing, and even inside dead animals.
Insurgents have also shown enormous skill in adapting to American countermeasures.
When roadside bombings began to rise last year, the Pentagon began rushing armored Humvees to most of its units in Iraq. Insurgents responded by building much bigger bombs.
Large artillery shells linked together in a series have inflicted multiple casualties, even on hardened steel vehicles.
Insurgents have also been adept at changing tactics. Until about a year ago, insurgents remained fairly close to the scene of the attack because they were using basic detonators such as wireless doorbells and car-alarm systems to set off the bombs.
When U.S. troops began spotting and killing the triggermen, insurgents began using cell phones and two-way radios instead. This allowed them to detonate hidden explosives from one to two kilometers away.
That move prompted the military to distribute electronic jamming devices on Humvees and other vehicles to block radio waves. But that has only solved a part of the problem.
Adaptive as ever, insurgents have begun deploying much more sophisticated and lethal types of IEDs, called shaped charges. Most of these manufactured bombs, designed to penetrate armored vehicles, are believed to be coming from neighboring Iran. And they are now being fitted with equally sophisticated detonating devices, aimed at bypassing electronic jammers.
Classified reports show that some of the shaped charges used in recent attacks against American convoys were armed with motion sensors and heat-sensitive infrared detectors to trigger explosions.
While U.S. military engineers and contractors grapple with the problems posed by evolving insurgent technology and tactics, commanders in Iraq are relying on several different methods to try to reduce IED casualties.
One of the methods involves a massive, 21-metric-ton vehicle called a buffalo. Its thick armor and an attached nine-meter mechanical arm give the U.S. military the ability to do what it could not do before - locate and disrupt IEDs before they can cause harm.
VOA recently rode on a buffalo in an evening mission with a group of Army combat engineers, who undertake this deadly task twice a day, six times a week. The so-called buffalo unit regularly patrols some of the worst IED-infested routes in Baghdad.
The buffalo's mechanical arm operator, Private First Class Edgardo Bauzo, describes one of the routes that runs through the insurgent neighborhood of Dora, where roadside bombs have killed several Americans in recent weeks.
"We have found posters that say, 'America, welcome to death' or 'You have come to take our blood to save Israel'," he said. "So, the route marks itself as [saying] we are here and we are ready to do damage."
For several hours, the buffalo, accompanied by two tanks and four Humvees, run laps around the area, scrutinizing every piece of suspicious looking item lying by the roadside. When an item appears to be a potential bomb, the buffalo's mechanical arm is activated to poke at it and to determine what it is.
In some places in Iraq where the buffalo is not available, U.S. troops have no choice but to conduct patrols on foot, armed with little more than metal detectors and shovels to uncover IEDs. Snipers are also sometimes used to kill insurgents trying to plant explosives.
But with casualties still mounting from near-daily IED attacks, the U.S. military is aware that much more must be done to stay ahead of its adaptive and determined opponents.