Video purports to show a passenger being subdued in a flight from Dulles International Airport on Monday. (Joe Willenkamp/YouTube)

(Update: Text from flight: ‘Scariest moment’ as passenger subdued after cockpit dash)

A United Arlines jetliner returned to Dulles International Airport on Monday night after takeoff when a passenger failed to comply with crew instructions, the airline said.

Local law enforcement officers met the plane at the gate at Dulles and detained the passenger, the airline said.

No passengers were injured and no weapons were found, said a spokeswoman for Dulles.

The airplane, Flight 1074, was carrying 33 passengers to Denver from Dulles. It was a twin-jet Boeing 737 with a crew of six.

A passenger aboard a United Airlines flight Monday night raced toward the cockpit screaming, forcing the plane to return to Dulles Airport. Here are excerpts from the conversation between the cockpit and air traffic control. (Audio courtesy: LiveATC.net)

The aircraft returned to Dulles soon after “because of a disturbance” on board, said Kimberly Gibbs, the spokeswoman for the airport.

She said the passenger who was removed was “transported to a local hospital for evaluation.”

The flight was scheduled to depart at 10:15 p.m., suggesting that it was not in the air long before it turned back.

One of the most common instructions given on takeoff is for all passengers to be seated with safety belts buckled. An announcement saying that passengers are free to move about the cabin generally somes after cruising altitude is reached.

Gibbs said that at about 12:45 a.m. Tuesday, the plane was on its way to Denver.

Meanwhile, video posted on the Reddit Web site purported to show scenes from on board the flight. It showed a dark-haired man with bruises below his right cheek and near his mouth. The man appeared to be in his 20s or 30s.

That conformed with an account published on the site indicating that people had subdued a man on board.

Whoever posted the account said it was relayed from one of the passengers. It said a man had run toward the cockpit, screaming. According to the account, “several large passengers” tackled the man before he ever reached the flight deck.

It was not clear what the man wanted.

Another video segment showed the man lying on what appeared to be an airplane cabin floor, adjacent to a bulkhead. In the video, several hands are holding down his head.

In audio that accompanies the video, the man groans and moans. At one point in the two-minute segment, he cries out “please stop.”

At least one of those pinning the man down appears to try to reassure him.

“We’re going to get you off,” the man says, “Relax, relax ... we’re getting you home.”

This story has been updated.