(CNN) -- A Delta Air Lines flight from Seattle to Beijing turned back after takeoff Thursday evening after a passenger assaulted a flight-crew member -- an incident that left both people and another passenger injured -- FBI and airport representatives said.
The man accused of attacking the crew member, a 23-year-old man from Florida, was arrested shortly after the plane returned to Seattle-Tacoma International Airport, FBI spokeswoman Ayn Dietrich-Williams said.
Delta Flight 129 was flying over or near Canada's western coast when a man assaulted a flight attendant in the first-class cabin, and several passengers stepped in to try to subdue the attacker, airport spokesman Perry Cooper said.
Details about what led to the alleged assault weren't immediately available.
Early reports that the suspect tried to break into the cockpit were incorrect, Perry said, adding that an investigation continues.
The plane, which had taken off at 5:24 p.m. PT, turned back and landed at the Seattle-Tacoma airport at 7:09 p.m. PT, flight-tracking website FlightAware shows.
The flight attendant and a passenger were taken to a hospital with non-life-threatening injuries, Cooper said, without giving further details about the injuries.
The suspect also was injured, but declined treatment from medics and was taken into custody, Cooper said.
The flight departed again for Beijing shortly after midnight local time Friday.
The suspect is due to make an initial appearance in federal court Friday at 2 p.m. PT in Seattle, the FBI said.
Delta described the flight's return as a "security incident with a passenger."
"The passenger was restrained onboard and was removed from the flight by law enforcement without further incident when the aircraft arrived back at Seattle," the airline said in a prepared statement.
There were conflicting reports soon after the incident. Initially, two people familiar with it told CNN on condition of anonymity that the man tried to enter the cockpit.
But Cooper subsequently said that was incorrect, and he and Dietrich-Williams described the incident only as an assault on a crew member.
Dietrich-Williams, the FBI spokeswoman, added there was no information to suggest that there was a national security threat.
The two anonymous sources also initially said that the Boeing 767 returned to the airport under a Department of Defense escort.
But representatives from Delta and the North American Aerospace Defense Command said no such escort happened.
The FBI Seattle field office maintains a regular presence at the airport, and is assisting and interviewing passengers from the flight, Dietrich-Williams said.
"The FBI's investigation is ongoing and more details about the incident will be provided and the charges announced at the subject's initial appearance in federal court," the FBI said.
Editor's note: This story has been updated to reflect the latest information from airport and airline officials and authorities.