Thousands of visitors have descended on the former Brunswick Naval Air Station for the Great State of Maine Air Show this weekend. 

The event showcases vintage aircraft and aeronautical stunt teams, but one type of aircraft is not welcome.

Drones were detected on Saturday, the first day of the two-day event, according to air show officials.

The unmanned remote vehicles create a “significant safety risk for both performers and spectators,” officials said in a statement.

Over the weekend, it is prohibited to fly drones in Brunswick, as well as in nearby communities of Bath, West Bath, Arrowsic, Phippsburg, Topsham and Bowdoinham, according to the Sagadahoc County Sheriff’s Office. (Brunswick is in Cumberland County but neighbors Sagadahoc County.)

“Advanced drone detection systems are in operation throughout the event,” air show officials stated in an online post. “Individuals who unlawfully operate drones in restricted airspace will be identified and arrested.”

Officials ask the public to report to police or air show staff any drones spotted near the air show, or any suspicious drone activity.

“There is a reason for the rules being in place,” Brunswick police stated on social media. “Please respect them because having to track them down takes officers away from the other duties they are trying to perform.”