A U.S. Army battalion commander was killed by a fellow soldier on Thursday in a shooting incident at Fort Bragg, N.C. The alleged gunman then shot himself and is in custody; a third soldier was slightly injured in the shooting.

An Army statement said the shooting victim belonged to the 525th Battlefield Surveillance Brigade. A battalion is a subordinate command within a brigade and is commanded by a lieutenant colonel. The battalion involved in today's shooting has not been identified.

A Defense official told ABC News that the shooting occurred this afternoon as the battalion was gathered for a safety briefing in advance of the upcoming July 4 weekend.

The safety briefings are usually held by commanders to reinforce good patterns of behavior during holiday periods.

The official says that at some point during the safety briefing an enlisted soldier broke out of formation and pulled a handgun to shoot the battalion commander. Another soldier was slightly injured during the shooting. The gunman then shot himself. He was taken into custody and is listed as being in serious condition.

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This official says it is unclear if the handgun the enlisted soldier used in the shooting was a personal weapon or military issue. Army bases usually keep firearms under lock and key at armories unless units are scheduled to use weapons at firing ranges.

The official said the incident occurred two blocks from the Corps' headquarters. An Army statement said, "Fort Bragg law enforcement and emergency responders secured the scene within minutes at the corner of Letterman and Armistead Streets."

At a press briefing late this evening Col. Kevin Arata, a spokesman for the XVIII Airborne Corps based at Fort Bragg, said, "This is a tragedy for our community. We don't yet know the reasons for the shooting, but are working with the unit and the affected families to help them through this difficult period." He added, ""Our prayers are with those who have been affected by this terrible incident."

Special Agents from the Army Criminal Investigation Command are investigating the shooting.