Capt. Zachary Martin, a Hawaii Marine and company commander who just returned from a six-month deployment to southern Afghanistan, lost three Marines and had about five more suffer very serious injuries.

Golf Company was involved in 15 to 20 major engagements against as many as 40 to 50 enemy fighters from a resurgent Taliban in the opium-producing region of Helmand province.

One threat increasingly stands out among the others across Afghanistan: the increasing use of roadside bombs. The Pentagon is trying to speed new resources — a new version of mine-resistant vehicles, more unmanned aircraft for observation and more route clearance and explosive ordnance removal teams — to the battlefield.

It's something that could be a benefit to Hawaii Marines. Martin and Golf Company were part of about 1,000 Marines and sailors with the 2nd Battalion, 3rd Marines, a unit that's still in the process of coming home.

Another 1,000 Marines with the 1st Battalion from Käneohe Bay will be leaving for Afghanistan in a couple of weeks.

U.S. military officials say "improvised explosive devices," or IEDs, are the No. 1 killer in Afghanistan, accounting for up to 80 percent of U.S. casualties. CNN reported that since 2007, the number of IEDs has jumped 350 percent.

"The IEDs are a huge threat," Martin said.

One of Martin's Marines, Lance Cpl. Larry Draughn, 22, had his life forever changed by a roadside bomb.

The Ohio man walked through a doorway separating farm fields in the village of Now Zad last May, and a bomb exploded. It may have been two land mines on top of an artillery round, but he's not sure.

"It just felt like you were inside a big chapel bell and somebody was hitting it with a sledgehammer," he said. Draughn lost one leg above the knee, the other below the knee, and part of his right hand.

The Oshkosh Corp. has received contracts worth $2.3 billion for 4,296 mine-resistant, ambush-protected all-terrain vehicles, a smaller version of the hulking MRAPs now in use. The smaller all-terrain vehicles, known as M-ATVs, also have a V-shaped hull to deflect blasts, but can better negotiate some of Afghanistan's treacherous and narrow mountainside roads.

The five-passenger vehicle is designed to replace up-armored Humvees.

The new vehicles "are being delivered by air (to Afghanistan) as fast as we can get them off the factory floor, with hundreds due to be fielded to our warfighters by year's end," Pentagon spokesman Geoff Morrell said Thursday.

The deadly nature of the roadside bombs was demonstrated again on Tuesday, when a massive IED exploded beneath an Army Stryker vehicle outside Kandahar, killing seven U.S. soldiers out of Fort Lewis, Wash.