PETERSON AIR FORCE BASE, Colo. (AP) — NORAD headquarters in Colorado have been evacuated after five suspicious packages were found, but the command’s control room team was working at a backup location several miles away at the time.

Officials say employees became suspicious of the packages Thursday because something looked “out of place.” They declined to elaborate.

No biological, chemical or radiological agents have been found. Other tests are under way.

About 1,500 people have been evacuated from the building on Peterson Air Force Base in Colorado Springs. The building is also headquarters for U.S. Northern Command.

NORAD is short for North American Aerospace Defense Command. The joint U.S.-Canadian command defends the skies over both nations.

A backup control room in Cheyenne Mountain is in use because of renovations at the headquarters building.

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