Is it a bird? Is it a plane? It was definitely a plane, and it created quite the stir on social media after it was seen circling Phoenix for several hours Thursday night.

Viewers reported seeing a plane "circle" above the Phoenix metro for at least five hours, and generated several theories as to what the plane was or what it was actually doing.

As it turns out, the plane belonged to the Phoenix Police Department.

Police would only say the plane was being used for a training operation, or to assist in an active investigation, in which case they cannot comment.