Hazardous Material teams responded to Samaritan's Purse in Watauga County Friday after officials say they received a white powdery substance in the mail.
The suspicious letter was sent to the Samaritan's Purse office in Boone, on the 800 block of Bamboo Road, Friday afternoon.
Officials have not confirmed what the substance in the package was, but did confirm that three people were in the room when the envelope was opened. They say those three show no signs of any illness.
The Federal Bureau of Investigation (FBI) is investigating the incident.
"Every investigative and safety precaution is being taken regarding this matter. Although the vast majority of white-powder letters are determined to be hoaxes, no incident is taken lightly," the FBI said in a statement released Friday evening. "Each incident is treated as a real event and the FBI and partners have leveraged the necessary resources to investigate these matters."
"A suspicious letter was received via the US mail today at the Samaritan's Purse headquarters in Boone, NC," Samaritan's Purse officials said. "It contained a white powdery substance and was immediately reported to the proper authorities who are investigating."
Law enforcement was called to the scene after the substance was discovered and they alerted the Hazardous Material team as a precaution.
WBTV is a media partner of The Charlotte Observer.