Strange sounds emanating from a mysterious building in the dead of night. White cars following families as they walk their dogs nearby. Science fiction movie? No, just Apple's latest project.

Residents of Sunnyvale, Calif., who live near a complex of buildings Apple started occupying in 2014 tell the San Jose Mercury News it's clear something is going on at the complex, where the sheet metal fences are 12 feet high and security is intense, but no one knows what.

One local says he hears "bangs," "thumps," and beeping (like a truck when it backs up) in the wee hours; another says he hears what sounds like a person "waving around" a big piece of sheet metal.

Both say there's also sometimes an odd whine or hum that increases in pitch (ABC 7 describes it as sounding like "some type of industrial machine ramping up") and is "loud enough to wake you." One family describes being followed by the aforementioned white Priuses when they walk their dogs near the complex, and say that if they get too close, they're "intercepted" by security guards who use clipboards to hide their shirt logos.

What does Apple have to say? "Yeah, no, we're not going to provide an official response," says a rep. But clues, including two recent permit documents describing a "repair garage" and an "auto work area" inside the complex, suggest Apple might be working on a car, likely some sort of high-tech automobile (electric or self-driving, perhaps).

Prior reports on the noises described some as sounding like "motors." Asked about the permits, the rep did confirm that Apple has, in the past, worked on projects related to cars.

But the people who applied for the aforementioned permits wouldn't comment on what exactly they were for, and not much else is known. (Yeah, it's probably a car.)

This article originally appeared on Newser: Apple's Calif. Complex Is Making Weird Noises

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