Low-flying, unmarked helicopters have been circling Santa Fe this week. But they're green, not black, and officials say there's a perfectly reasonable explanation: to get ready for a possible nuclear attack.

An alphabet soup of federal agencies—including the FBI and the Defense Department—are nearing the end of a five-day training exercise in Albuquerque and Santa Fe, Energy Department spokeswoman Jessica Szymanski tells SFR in an email.

It has a name: "Prominent Hunt 17-2." (Seriously.) The agencies have been doing it twice a year since 2012, Szymanski says, making a point of disabusing SFR of the notion that helicopters in the sky over our fair city in preparation for the end of the world might have anything to do with President Donald Trump's ongoing game of rhetorical one-upmanship with North Korea's young dictator.

"The exercise is for operational readiness to respond in the event of a nuclear detonation in the US or overseas," her email goes on to say. "It is not in response to any ongoing world events."

Santa Fe Municipal Airport Director Cameron Humphres says the Department of Energy notified the city's air traffic control tower last week that two helicopters for the exercise would use the airport as an operations base.

Helicopter pilots aren't required to file flight plans with the Federal Aviation Administration, according to Humphres. The FAA’s Flight Standards District Office in Albuquerque has informed the airport, however, that several people made complaints about the operation.Residents have reported seeing the helicopters over Cerrillos Road and also St. Francis Drive, as well as near Nava Elementary School and the Sangre de Cristo foothills.The Department of Energy includes the National Nuclear Security Administration and oversees operations at Los Alamos National Laboratory.