A worker at a Fort Detrick bioterrorism lab has tested positive for exposure to anthrax hours after low-levels of the spores were found in a hallway and an administrative room, according to Army officials.

Another person at the U.S. Army Medical Research Institute of Infectious Disease may also have been exposed, spokesman Chuck Dasey said. No employees have tested positive for the disease.

Both employees have started antibiotics as a precaution and have been previously immunized, according to a statement.

Although there are no indications the surrounding community is in danger, about one hundred people in the area of the lab were evacuated. Those employees will be examined and given antibiotics if necessary.

The air containment system in the lab did not appear to be malfunctioning, the statement said. It described the contamination as "highly localized," as samples from the surrounding areas tested negative.

Contamination testing began after a flask in the lab was found with residue on it.

The Institute studies biological threats that require containment. It uses anthrax to develop vaccines for the military.

The Associated Press contributed to this report.