A Muslim family demanded an apology from the United Airlines after they were removed from a flight at Chicago’s O’Hare International Airport citing security issues. The family of five were removed after they requested an additional strap for their youngest daughter’s child booster seat.

Ahmed Rehab, executive director of Chicago’s Council on American-Islamic Relations, which is representing the family, said that when the parents tried to enquire why they were being removed the crew asked them to exit “peacefully” and wait for further instructions.

“We are tired of Muslim-looking passengers being removed from flights for the flimsiest reasons, under a cryptic claim of ‘security’,” the CNN quoted Ahmed as saying.

The United Airlines said that the family was requested to exit from the flight because of their daughter’s safety seat. According to the airlines, the seat did not conform to the federal safety regulations.

“They were originally scheduled to fly on SkyWest 5811, operating as United Express from Chicago O’Hare to Washington, D.C., but we rebooked them on a later flight because of concerns about their child’s safety seat, which did not comply with federal safety regulations,” United said in a formal statement. “Both United and SkyWest hold our employees to the highest standards of professionalism and have zero tolerance for discrimination.”

However, Rehab said that the parents were told by a United attendant at the gate that the computer system was down and instructed them to bring the seat aboard when they tried to check it there, the Chicago Tribune reported.

Later, when the father asked a flight attendant if they can get another strap for the seat, the attendant said she did not know what he was talking about and walked away. A short while later another attendant came and removed the booster seat, following which the pilot asked them to leave the plane.