Authorities continue investigation of U.S. Airways incident

Authorities continue to investigate a Saturday incident involving a commercial flight at McCarran International Airport, but have made no arrests.

FBI agents and Las Vegas police responded to the airport Saturday after U.S. Airways flight 399, which was bound for Phoenix, had to return because of a mechanical problem. The flight originally left Las Vegas at 4:30 p.m.

After the plane landed at McCarran, "some sort of threat was made" by a passenger, airport spokeswoman Candice Seeley said on Saturday. She said authorities did not believe the threat and the mechanical problem were related.

On Thursday, FBI spokesman Joseph Dickey refrained from using the term "threat" to describe the incident.

"I'm just going to say there was an incident involving the flight," he said.

Dickey said investigators have questioned a couple of people about the incident, including a passenger on the flight. The passenger lives in Las Vegas, he said.

Although the incident occurred on Sept. 11, Dickey said, it "is in no way related to any terrorism activities."