An administrative building at the military base in Arlington, Virginia, was evacuated after several people reported "nose bleeds and burning sensations" from being exposed to a chemical attack from a hazardous substance in a letter they had received and opened.

Here's what happened

Police reported to a hazmat incident at Joint Base Myer-Henderson Hall after several people were exposed to a hazardous substance that was sent there Tuesday.

Three people were sent to the hospital, and total of eleven were injured.

A Marine official released a statement with more details about the incident.

"An envelope containing an unknown substance was a received, today, aboard Joint Base Ft. Mayer-Henderson Hall," the statement read. "Personnel in the affected building took immediate preventative measures by evacuating the building."

"Base officials and are coordinating with local HAZMAT teams and FBI," the statement continued. "Several Marines are receiving medical care as a result of this incident. No additional details are available at this time a as the investigation is ongoing."