HARRISBURG - The first wave of a 2,200-person Pennsylvania Army National Guard unit, consisting of soldiers drawn from around the state, begins traveling this week to training at a base in Mississippi in advance of combat deployment to Iraq this summer.

Headquartered in Washington County, the 2nd Brigade combat team of the storied 28th Infantry Division represents the Pennsylvania Army National Guard's largest contribution to the Iraq war so far, and will be the state's largest combat deployment since World War II, Guard spokesman Capt. Cory Angell said.

Soldiers learned more than a month ago that they were being mobilized for duty in Iraq.

"The majority of communities across the state will have somebody from that area that's going to be under this mobilization," Angell said Tuesday.

Headquarters staff and other key personnel will ship out on Thursday to Camp Shelby, Miss., followed by the other units in installments over the next month. Their gear is being shipped south in 180 rail cars.

About 1,100 Pennsylvania Army National Guard soldiers from an armor and artillery unit doing combat security are due back in February after they complete a one-year stint in Iraq. Their ranks are filled largely from Pittsburgh, Scranton and Wilkes-Barre.

Roughly 400 others assigned to a variety of tasks are also posted in Iraq and should return to the United States sometime in the next year, Angell said.

Another 750 are serving in Task Force Dragoon - a mixture of Philadelphia and Pittsburgh Guardsmen - and arrived in Iraq within the past month, Angell said.

The 2nd Brigade combat team is composed of infantry, armor, artillery, engineers and support and will probably arrive in Kuwait in mid-June, then be sent into Iraq for a year. The brigade will be combined with Guard units from at least eight other states to perform security and stabilization operations.

Three Pennsylvania Guard soldiers were killed in action in Iraq last year - Sgt. Sherwood Baker of Plymouth, Spc. Mark Kasecky of McKees Rocks and Spc. Carl Curran II of Union City, Erie County, a graduate of Karns City High School.