Aviation authorities and the FBI are investigating reports that someone was flying with a jet pack near Los Angeles International airport on Sunday.
Two airline flight crews reported seeing what appeared to be someone in a jet pack as they were on their final approaches to LAX early in the morning.
FBI spokeswoman Laura Eimiller told the Los Angeles Times that agents at the airport were responding after pilots notified the control tower about the incident.
Recordings of communications between the pilots and air traffic control tower have been obtained by US media outlets.
In the recording, one pilot says: "Tower, American 1997. We just passed a guy in a jet pack."
The controller says: "America 1997, okay - were they off to your left side or right side?"
The pilot replies: "Off the left side, maybe 300 yards or so, about our altitude."
A few seconds later, another pilot tells the tower: "We just saw the guy pass by us in a jet pack."
The controller tells the pilot to "use caution", adding: "Person in a jet pack reported 300 yards south of the LA final at about 3,000ft."
An unidentified person can then be heard saying: "Only in LA."