A group of seven people protesting the war and nuclear weapons were apprehended Sunday by authorities when they crossed onto Offutt Air Force Base.
A Des Moines Catholic Worker who led the group, Frank Cordaro, said about 35 people gathered outside the base in Bellevue, which is home to the Strategic Command.
Offutt spokesman, Lt. Bob Everdeen, said seven people who were detained were issued "barment" letters.
The letters mean that if within the next year any of the seven cross again onto the base they could be arrested and face charges. The borders of the base of demarcated by a line on the ground.
Cordaro has served six six-month prison terms for violating such letters by crossing onto the base.