About 200 demonstrators tried to enter the National Air and Space Museum on Constitution Avenue Saturday afternoon.
A spokesperson with the museum says when a security guard tried to stop the group -- because museum policy prohibits anyone from entering with signs - demonstrators blocked him. A second guard used pepper spray on at least one person and the crowd dispersed.
Meanwhile, members of CODEPINK and Veterans for Peace who were able to enter dropped a three-story banner inside the museum to protest military action around the world. The banner read, "No Drones, Stop the Afghanistan War."
Police say one woman was arrested. The museum is expected to open on time today.