"No one should be subjected to discrimination when traveling, and today's message sends a clear signal to the airline industry that we are prepared to investigate and take action whenever passengers' civil rights are violated," says US Transport Minister Pete Buttigieg in a statement.
The incident occurred in May 2022. The group was on its way from New York to Budapest in Hungary, but was denied boarding on a connecting flight in Frankfurt, reports NBC.
The reason was that some in the group had refused to wear face masks.
A video of the incident showed that Lufthansa's staff told them that "everyone must pay" for the mistakes made by a few and then defined "everyone" as "Jews who came from JFK (airport in New York)".
Lufthansa says in a statement that the company has fully cooperated with the transport department during the investigation.