WASHINGTON, D.C. - After several employees received an anonymous threat via email, the USDA announced the closure of several offices in multiple states while looking into the matter. More recently, some of those offices have reopened with higher security measures, however some remain closed.

"Without getting into detail of the email message, USDA continues to work closely with federal and local law enforcement, including the FBI, to determine whether the threat is credible," USDA spokesman Matthew Herrick told ABC News.

USDA agencies affected by the threat included Food Safety and Inspection Service, as well as Forest Service, and even four buildings at the Colorado-based Natural Resources Research Center campus employing 1,000 people were closed.

The emails were received late Monday night, August 29th, prompting the closures and a message from Agriculture Secretary Tom Vilsack cautioning employees to be aware of their surroundings and report any suspicious activity, informing them they could telework or take authorized leave.

The USDA reopened offices in the following locations:

• Colorado
• Maryland
• North Carolina
• Kearneysville, West Virginia

Offices in Hamden, Connecticut, and Leetown, West Virginia, continue to remain closed until further notice, and Herrick told the news source that the USDA is still working with law enforcement.

AndNowUKnow will continue to follow this story as it develops further.

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