Authorities in Tennessee say deputy U.S. marshals shot and killed a man on railroad tracks in Johnson City after they tried to serve a warrant.

Tennessee Bureau of Investigation spokesman Josh DeVine said in a statement that two marshals based in the U.S. Marshal's Greeneville office were trying to serve the warrant Tuesday evening when the wanted man, 39-year-old James K. Maher, brandished a knife.

DeVine says the situation escalated and the two marshals fired their guns at Maher, who died at the scene.

The shooting occurred on the Norfolk Southern Railroad tracks adjacent to the Veterans Affairs Medical Center campus.

The TBI, which is investigating the shooting, declined to identify the two deputy marshals involved.

It isn't known why Maher was wanted.