BELTSVILLE, Md. — A large fire has damaged a U.S. Department of Agriculture facility outside the nation’s capital. No one was hurt.

Prince George’s County fire/EMS department spokesman Mark Brady said it took firefighters about 45 minutes Tuesday to knock down most of the flames at a one-story row of workshops inside the Beltsville Agricultural Research Center in Maryland.

Bureau of Alcohol, Tobacco, Firearms and Explosives spokesman David Cheplak says arson and explosives agents are on the scene.

He said in an email late Tuesday that there does not appear to be evidence that a criminal act occurred. Cheplak emphasized that the investigation is still open.

The Beltsville facility was one of six USDA locations around the country that closed for several days for security enhancements following threats to employees.