At least a dozen dead birds have been found at the Swimming River Reservoir in Middletown Township as reports of dead birds continue to surface across several New Jersey counties.

Sightings at the reservoir began over the weekend and were confirmed Monday through drone flights over the area. Officials warn some images may be disturbing.

Drone video taken Sunday just before dark showed dead and dying Canada geese, including birds spinning in circles — a behavior seen in past cases involving bird flu.

The reservoir is owned and operated by American Water. The company said there is no risk to the water supply. A bald eagle monitor on scene expressed concerns about a nearby nest.

The New Jersey Department of Environmental Protection is also aware of the sightings. At least a dozen dead birds have been confirmed along the reservoir so far.