Grand Traverse County - Dozens of people have spotted mysterious low-flying helicopters but no one seems to know who they belong to.

For a week, Grand Traverse County dispatchers have been fielding calls from residents concerned about unfamiliar helicopters near Chums Corner.

Jason Torrey, Grand Traverse County Dispatch Deputy Director says, "We got about 30 calls in a short period of time. Some people are scared because they are flying low and are not well lit, if lit at all. The report is that one helicopter is chasing another."

Dispatchers called the FAA and Cherry Capital Airport, but nobody seemed to know where the helicopters came from.

Airport Director, Kevin Kline says, "It was a mystery to us because we did know it didn't originate here at Cherry Capital."

Kline also made calls to the FAA, but says he got a vague answer.

Kline says, "The FAA was aware of the operation. They ensured us that they were in compliance with rules."

But what residents say they saw contradicts nighttime flying rules; an aircraft must have lights on.

We've contacted the Traverse Narcotics Team, Michigan State Police, Sheriff's Office all have said they're not responsible for the helicopters. Our calls to Camp Grayling and the FAA have gone unreturned.