(KMOV.com) - Sightings of odd and strange aircraft were being reported over the St Louis on Thursday.
Several viewers told us about planes trailing smoke over Alton and black helicopters over South St Louis, and even a sighting of a drone over North St Louis.
Many of the aircraft are part of this weekend’s Spirit of St Louis Air Show in Chesterfield and were out practicing, including the Blue Angels who were spotted over Chesterfield, but no one has an explanation for the suspected drone that some saw over Grand and Natural Bridge.
"It was circling around and circling around like it was looking for something,” one witness told News 4.
A posting on KMOV’s Facebook page stated the drone then headed up Grand towards I-70.
St Louis Police have shown an interest in using drones but a police spokesperson says they do not own any drones.
The group, Drone Free StL suspects it might have been a person using the drone as a hobby. The group said unless authorities regulate how drones are used, what happened Thursday could be a regular occurrence.
“That's the area where we know they're legal, if people keep them below 400 feet and within a line of sight," said John Chasnoff of Drone Free StL.