Southwest Airlines planes at San Francisco International Airport last month. (David Paul Morris/Bloomberg News)

A civil rights group said Tuesday that it has filed a lawsuit against Southwest Airlines on behalf of a Muslim man who was removed from a flight before takeoff in April and interrogated by the FBI after talking on his phone in Arabic.

The Council on American-Islamic Relations (CAIR) said in a statement that its San Francisco office filed the federal discrimination lawsuit Tuesday on behalf of Khairuldeen Makhzoomi, a U.S. citizen who came to the country as a refugee from Iraq. The complaint says an FBI agent later told Makhzoomi that he had been removed from the plane because he had been speaking in Arabic, suggested that he apologize to the airline for the incident and offered some advice: “Next time you are flying, don’t use your phone, just sit there.”

Makhzoomi, who was then a student at the University of California at Berkeley, had boarded Southwest Flight 4620 at Los Angeles International Airport, heading home to Oakland, and was talking to his uncle excitedly about having just attended an event where he heard former U.N. secretary general Ban Ki-moon speak, according to the complaint. Makhzoomi’s conversation aroused the suspicions of another passenger and the flight crew, according to the complaint and media accounts at the time. A Southwest employee and local law enforcement officers ordered him off the plane, searched him and questioned him, the complaint says.

The complaint says the Southwest employee admonished Makhzoomi for speaking in Arabic given the prevailing political climate and demanded to know whom he had been speaking to. “You know the environment is very dangerous,” the employee allegedly said. The complaint says Makhzoomi — who is now studying at Georgetown University — was singled out although many other passengers were talking on their phones.

CAIR has previously said that the incident was one of several instances of “flying while Muslim” bias, in which airlines have removed a Muslim person from a flight because of an imaginary threat.

A spokesman for Southwest said late Tuesday that the airline could not comment on pending litigation.  Earlier, the airline said its crew had made the decision to investigate after a passenger overheard “potentially threatening” comments on board the aircraft and turned the matter over to law enforcement.

“Safety is our primary focus, and our Employees are trained to make decisions to safeguard the security of our Crews and Customers on every flight,” the company said in a statement at the time. “We would not remove a passenger from a flight without a collaborative decision rooted in established procedures.”

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