The NAACP has issued a travel advisory against American Airlines, warning African-American travelers to tread lightly, for their safety might be compromised if they choose to fly with the airline.

“The growing list of incidents suggesting racial bias reflects an unacceptable corporate culture and involves behavior that cannot be dismissed as normal or random,” NAACP President Derrick Johnson said in a statement.

The NAACP pointed to four instances with American airlines in a news release.

–Activist Tamika Mallory kicked off flight, ‘disrespected’ by pilot–

One incident involved a Black man who had to give up his tickets when he “responded to disrespectful and discriminatory comments” made by two “unruly white passengers,” and another involved a Black woman and her infant who were removed from a flight when she asked that her stroller be removed from checked baggage before she got off the plane.

CEO Doug Parker said in a memo issued on Wednesday that he was “disappointed” by the travel advisory.

“We do not and we will not tolerate discrimination of any kind,” Parker said. “We have reached out to the NAACP and are eager to meet with them to listen to their issues and concerns.”

However, Johnson said that the travel advisory would remain in effect until the NAACP had seen that its concerns were addressed.