Four Georgia-based fighter pilots have been restricted from flight duty after an unauthorized low-altitude flyover over the practice field of the Carolina Panthers.

The four A-10C Thunderbolt IIs flew at a low altitude over Bank of America Stadium in Charlotte, North Carolina on Monday, Air Force Times reported. The airmen were based out of Moody Air Force Base in Georgia. The planes were from the 74th Fighter Squadron at Moody, which is near Valdosta, Georgia.

"As professional airmen we take aviation safety very seriously," Air Force colonel Thomas Kunkel said in a statement. "As we look into the circumstances of this incident we are working with the FAA to ensure both civil and military aviation instructions were complied with."

The pilots flew low enough they were able to wave at the players, Carolina Panthers Coach Ron Rivera told the AP.

The NFL said it had no knowledge of the flyover before it occurred. The FAA, however, said the pilots had requested permission from the tower before the flyover. The request was approved, the FAA said, but the altitude of the pass is being investigated.

The Air Force said the planes had taken off from Charlotte Douglas International Airport as part of a training exercise from Charlotte to Moody, North Carolina when they flew over the stadium.