MINNEAPOLIS (WCCO) – A misunderstanding between a flight attendant and air marshals involving a gun led to some tense moments aboard a United Airlines flight.

The plane landed late Monday night at the Minneapolis St. Paul-International Airport. Witnesses say a police officer boarded the plane before it arrived at the gate.

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WCCO’s Reg Chapman spoke to a woman on the flight, and the airline, about what happened.

The plane landed at the MSP Airport around 11:30 p.m. Monday, but it never made it to the gate. While the plane was sitting on the runway, several police cars surrounded it.

Passengers on board watched and wondered what was going on.

“There was nothing notable on the flight at all that evening,’ said Jennifer Bergman.

From seat 15C, Jennifer Bergman waited patiently as the plane she was on from Newark finally arrived home, at MSP.

“The pilot came on and said to us that our gate was occupied and we had to sit on the tarmac for a couple of minutes until the gate was cleared and we could proceed forward. And then all of a sudden I noticed lights coming towards the plane in every direction,” Bergman said.

Bergman says when the lights got closer, all she could see were police cars.

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“The doors opened and the police boarded the airplane, there was about four of them. They stopped in first class, pointed to two gentleman on each side of the aisles and asked them to go with them. The men, without incident, got up and left the plane,” Bergman said.

Bergman says officers got back on the plane and questioned the passengers in first class who were sitting near the men placed into custody.

“The pilot came on and said ‘Unfortunately I am unable to tell you at this time what is going on but the matter has been taken care of,’” Bergman said.

WCCO listened to a recording of the air traffic control radio, where the pilot tells the tower the reason they declared an emergency.

In a statement the TSA said: “A Federal Air Marshal on official business onboard a flight was mistaken for a passenger by a flight attendant. Protocols for notification of law enforcement presence aboard an aircraft are in place to avoid incident like this.”

“It’s really concerning to me. My understanding they had guns, they were on the plane and they weren’t following protocol,” Bergman said.

A spokesperson for United Airlines said “The safety and security of our customers and employees is our top priority.”

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The FBI is leading that investigation into the incident. The FBI says the miscommunication was between flight crews and the marshals, and there was no danger to the public.

Reg Chapman