PORTLAND, Ore. — A United Airlines flight from Dulles International Airport that was diverted to Chicago for security concerns finally landed about 1 a.m. Wednesday in Portland.

United spokesman Rahsaan Johnson tells KGW that passengers on Flight 251 from Dulles were taken off at O’Hare International Airport Tuesday night and re-screened through security.

He says two or three passengers who had not been following crew instructions were not on board the plane when it continued to Portland International Airport. He couldn’t say whether they were detained.

Johnson says another passenger was ill, which may have complicated the situation on the plane.

Information from: KGW-TV