Several passengers helped subdue the alleged attacker until the plane returned to Seattle, Sea-Tac Airport spokesperson Perry Cooper told The Washington Post.
"The passenger was restrained onboard and was removed from the flight by law enforcement without further incident when the aircraft arrived back in Seattle," a Delta spokeswoman said in a statement to The Post.
The flight attendant and another passenger who helped to restrain the alleged attacker were injured during the incident, the spokeswoman said. The severity of these injuries are unknown at this time.
The unruly passenger was taken into custody by the Port of Seattle Police Department. Police and the FBI have been questioning passengers, according to Cooper, who added, "Right now, we have no information to suggest this was a national security threat."
Cooper denied news media reports that said the subdued passenger tried to enter the plane's cockpit.
"We've been told he did not try to enter the cockpit door," Cooper said.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)