(Reuters) - Southwest Airlines Co was sued on Tuesday by an American citizen who came to the United States as an Iraqi refugee, and said he was removed from a California flight after another passenger became unnerved upon hearing him speak in Arabic. Khairuldeen Makhzoomi said he is seeking compensatory and punitive damages for civil rights violations, discrimination and emotional distress stemming from the “Islamophobia” underlying the April 6, 2016 incident, which began as he awaited takeoff to Oakland from Los Angeles.

FILE PHOTO: A Southwest Airlines plane is seen at Los Angeles International Airport (LAX) in the Greater Los Angeles Area, California, U.S., April 10, 2017. REUTERS/Lucy Nicholson/File Photo

Southwest had no immediate comment. The complaint was filed with the U.S. District Court in San Francisco.

Makhzoomi said he had been seated and talking with his uncle by phone, after attending a dinner featuring United Nations Secretary General Ban Ki-moon, when two police officers and Southwest employee Shoaib Ahmed removed him from the plane.

The plaintiff, then a 26-year-old public policy student at the University of California at Berkeley, said he was “singled out” by the Dallas-based carrier for speaking in Arabic, though he was doing nothing wrong and was not a security threat.

He also said Ahmed, who is also a defendant, admonished him by saying, “Why are you talking in Arabic? You know the environment is very dangerous.”

Makhzoomi said he was released by local law enforcement and the Federal Bureau of Investigation after hours of questioning and being “invasively searched,” but that Southwest refused to rebook him, and instead refunded his ticket. He later flew home on Delta Air Lines.

“Southwest was and is well aware of the prevalent stereotypes and sentiments associated with Islamophobia,” the complaint said, “and knew or should have known that they cannot simply remove Arabic speaking passengers without having a valid reason or concern.”

Zahra Billoo, executive director of the San Francisco Bay Area office of the Council on American-Islamic Relations, said Makhzoomi tried to resolve the dispute out of court, but Southwest’s response proved “unsatisfactory.”

“We want to make sure that what happened to Mr. Makhzoomi does not happen to others,” Billoo, a lawyer for the plaintiff, said in an interview.

Makhzoomi is now pursuing graduate studies at Georgetown University’s Walsh School of Foreign Service, Billoo added.

Southwest said soon after the incident that its employees followed proper procedure, and that the “content” of Makhzoomi’s talk with his uncle, not the language, had prompted action.

The case is Makhzoomi v Southwest Airlines Co et al, U.S. District Court, Northern District of California, No. 18-00924.