Passengers told KOKI-TV via Twitter that a man was singing loudly in his seat and violently thrashing and dancing to the music that he was listening to.

Passenger Lisa Zimmerman told KOKI that a flight attendant asked the man to quiet down on multiple occasions and even moved a woman who was sitting next to the man.

Zimmerman said after officials made a couple of attempts to get the man to quiet down, "he flipped out."

Passengers sitting nearby reported that the man threatened to harm the flight attendant if she bothered him again and he told her she "will regret it.”

An air marshal reportedly stepped in to try to calm the situation, but when she intervened, passengers said the man raised his fists to the marshal.

After the landing, airport police boarded the plane and arrested the passenger. Zimmerman said he was screaming about God, Judgment Day and how everyone needed to repent of their sins. He also claimed that he had authority over the police because cops are "sin."

The FBI said its agents took custody of the man, and the U.S. Attorney's Office is looking at possible charges, since threatening a member of a flight crew is a federal offense.

Delta 1156 took off again for Atlanta around 2 p.m. Wednesday.

Here's a statement from U.S. Attorney R. Trent Shores about the incident:

“Today, a Delta flight traveling from Portland to Atlanta was diverted to Tulsa due to the alleged conduct of an unruly passenger. Federal Air Marshals on the plane successfully deescalated and controlled the situation, and the flight landed in Tulsa without further incident. The passenger-at-issue has been taken into custody. Law enforcement officials with the Federal Bureau of Investigation will investigate this matter moving forward. The Transportation Security Administration, Homeland Security Investigations, and Tulsa International Airport authorities assisted in the response and initial investigation.

"The United States Attorney's Office will review whether the alleged unruly conduct violated federal law. I am thankful no one was hurt and that the other passengers may resume their travel to their intended destination. I commend the Federal Air Marshals who reacted decisively in this situation. Their efforts – combined with the resulting joint investigation – remind us all that our local, state, and federal law enforcement partners are working together to ensure the safety and security of the traveling public."