United Airlines passengers removed from flight at Denver airport

DENVER - It's not entirely clear why some passengers were removed from a plane at Denver International Airport on Wednesday. United Airlines issued a statement suggesting that the passengers were "re-accommodated" onto another flight.

A spokesperson for the Denver Police Department confirms to 9NEWS that Denver Police officers were called to DIA on Wednesday, but declined to elaborate any further.

Flight 227 left DIA bound for Los Angeles nearly three hours late. It was scheduled to depart at 1:50 p.m., but ended up leaving at 4:32 p.m.

"Our crew followed recognized, industry standard procedures and re-accommodated some passengers on another flight. We are investigating this matter," read a Thursday morning statement from United. A United spokesperson declined to elaborate any further as well.

The United crew apparently noticed certain patterns they are trained to spot. Sources tell NBC News airline employees are trained to look for certain behaviors such as how a ticket is paid for, how often passengers get up to use the restroom, and even who their traveling companions are.

A spokesperson for the FBI, Kathy Wright, confirmed to 9NEWS that federal investigators were originally called to the scene after receiving a call on a "possible suspicious incident." Wright said eventually "we determined that it was not an FBI matter."

Passengers say a bomb-sniffing dog was brought onto the plane and passengers in the first-class cabin we're asked to go back to coach for a brief amount of time according to passengers on the plane.

John Sloan of Oxnard, California, was on board the flight on Wednesday.

"I have never seen flight attendants so scared in my life. Everything turned out OK, but it was not a very good feeling. It would have been nice to have been updated though this process," he told 9NEWS by phone.

Sloan says seven men were escorted off of the plane. Two of them were sitting in coach. The other five were sitting in first-class, he says. All were re-booked onto another flight according to United.

Sloan says the men were attempting to change seats with other passengers. Another passenger, who doesn't want his name used, says the men were also trying to move luggage while the plane was getting ready to push back.

Passengers tell 9NEWS all of the men looked to be "Middle Eastern," but United will not confirm the identity of the seven men.

Nothing criminal was found, and the flight was allowed to continue on to California.

Passengers also tell 9NEWS that former head coach of the Denver Broncos, Mike Shanahan, was seated in first class while this was all going on. Shanahan could not be reached for comment, and a spokesperson for the former coach simply told 9NEWS that he was "out of town."

There have been no arrests and investigators say there is no criminal investigation in connection to the incident.

If you have any information about what happened on Flight 227 on Thursday, please e-mail us at chris.vanderveen@9news.com.