A mystery drone flight sparked UFO fears in New Jersey.

Dramatic footage shows puzzling unmanned aerial vehicle activity in the skies over Delran, Moorestown, and Cinnaminson, New Jersey, on December 9.

Resident Keith saw four aircraft flying in identical patterns every 30 minutes, starting at 7:25 pm.

Some devices flew lower than passenger planes and had bright flashing lights, with one passing so close that its small propellers were visible.

Keith said: 'It did sound like a passenger jet but not as loud… it looked like the size of an SUV, but could've been even larger.'

Attempts to zoom in for a more detailed clip were unsuccessful due to the distance.

The strange drone activity, lasting less than 10 minutes per sighting, left locals questioning the unusual low-altitude flights across the region.