Authorities say no charges have been brought against four people removed from a Spirit Airlines flight in Baltimore headed for Chicago on Tuesday after they removed for “suspicious activity” on board. (WUSA9)

The head of an Islamic civil rights organization on Tuesday warned of increased racial profiling of Muslims after a plane was diverted from takeoff in Baltimore when a passenger raised concerns about the “suspicious activity” of a traveler whose companions included people who reportedly appeared to be of Middle Eastern descent.

“That just indicates it’s what we suspected all along. It’s flying while Muslim,” said Ibrahim Hooper, spokesman for the Washington-based Council on American-Islamic Relations.

Hooper said the incident fit a familiar pattern after major terrorist attacks occurred involving Islamic extremists, such as Friday’s commando-style attacks in Paris by ISIS militants. But singling out people based only on their appearance has led to mistreatment of Muslims and other people who were thought to be Muslim based on their appearance and dress, such as Sikhs, Hooper said.

“I’m just concerned about the rise of anti-Muslim incidents nationwide,” Hooper said. “The argument is better safe than sorry but, yeah, that works if you’re not the one being targeted.”

Four passengers on a flight at Baltimore-Washington International Marshall Airport were asked to exit the plane after another passenger alerted a flight attendant of “suspicious activity” on board, according to officials at Spirit Airlines. No one was injured.

The flight — Spirit Airlines 969 — was scheduled to leave BWI around 6 a.m. to head to Chicago’s O’Hare International Airport. Airline officials would not say what the suspicious activity involved.

The Chicago Tribune, quoting passengers after the plane landed, said at least two of the people removed from the plane appeared to be of Middle Eastern descent, and one was watching a news report on his mobile phone as the plane taxied toward the runway.

The flight attendant notified the captain of the passenger’s concerns and “out of an abundance of caution, the plane returned to the gate,” Spirit Airlines spokesman Stephen Schuler said in a statement.

Law enforcement officers removed the four — three men and a woman — from the plane for questioning. First Sgt. Jonathan Green, a spokesman with the Maryland Transportation Authority Police, said the passengers who were removed had not been arrested and they had not been charged with a crime.

“They were removed from the aircraft at the captain’s request,” Green said. “They were taken to the station for questioning.”

Just before 10 a.m., one of the passengers — a man — was released from questioning by authorities, according to Green.

All of the other passengers on the jet were deplaned for a brief time, according to the airline. The plane and the luggage were later cleared by the Transportation Security Administration, and it was scheduled to “take off shortly,” the airline’s statement said just after 9 a.m.

TSA spokesman Bruce Anderson said while they were aware of the incident and “monitoring it” the agency was not the lead and referred questions to the local authorities.

Green said he could not say what the suspicious activity is that prompted officials to remove the four passengers. “That will come out in the investigation,” he said.