A Missouri soldier has been killed in Afghanistan.

The Department of Defense says 29-year-old Specialist Bradley L. Melton of Rolla was killed by an improvised explosive device when insurents attacked his unit in Zabul province.

Melton was one of four soldiers killed in the attack. Also killed were:

Staff Sgt. David D. Self, 29, of Pearl, Miss. He was assigned to the Fires Squadron, 2nd Stryker Cavalry Regiment, Vilseck, Germany; Pvt. Lamarol J. Tucker, 26, of Gainesville, Fla.; and Pvt. Cheizray Pressley, 21, of North Charleston, S.C. They — and Melton — were assigned to the Brigade Troops Battalion, 1st Stryker Brigade Combat Team, 25th Infantry Division, Fort Wainwright, Anchorage, Alaska.