An Alaska Airlines flight was forced to make an emergency landing on Saturday evening after a passenger threatened to kill all the other passengers on the plane, according to airport officials.

The incident took place shortly after the Alaska Airlines Flight 422 took off from the Seattle-Tacoma Airport for Chicago's O'Hare Airport at approximately 11 p.m. on Saturday, according to Peter McGraw, spokesperson for the airport.

'Die in the Name of Jesus'

Alaska Airlines Emergency Landing
A still from the video that is being circulated on social media. Twitter

The man, who has not yet been identified, was unarmed and started becoming "extremely belligerent and physically aggressive during the ascent," Ray Lane, external communications manager for Alaska Airlines, said in a statement. The incident took place about 20 minutes after the plane's departure, causing the aircraft to return to Seattle.

Video footage shot by a fellow passenger that is being widely circulated on social media shows the man walking in the aisle while shouting that he would kill everyone on board. "I'm going to kill everybody on this plane. Die in the name of Jesus," the man says before he is taken down by fellow passengers, who reassure the other passengers that it is going to be okay.

The man can be seen wearing a face mask as are other passengers on board the aircraft, as is mandatory by the airline. Watch the video below:

Subdued by Police Officer Onboard

According to Lane, the man was subdued by the flight crew, two passengers and a law-enforcement officer who happened to be on the flight. According to a passenger on the flight, one of the men who helped restrain the unhinged man was actually a police officer in Chicago and both men should be considered heroes.

After the passengers had the man restrained, a flight attendant announced over the loudspeaker that the plane was going to land at the nearest airport, adding "we have everything under control." The flight was canceled and all the passengers were booked on the next available flight to Chicago.

After the flight landed in Seattle, police took the man into custody without incident and booked him into the King County Jail for harassment.