Four passengers were removed from a Chicago-bound flight at Baltimore-Washington International Thurgood Marshall Airport on Tuesday morning after passengers who appeared to be Muslim viewed what another passenger thought was an ISIS video, officials said.

Spirit Airlines Flight 969 was taxiing to the runway when the flight crew decided to return to the gate, reported the Chicago Tribune. Once at the gate, the captain asked police to remove three men and a woman from the plane, who are now being investigated.

"While the aircraft was taxiing to the runway, a passenger alerted a flight attendant of a passenger engaged in suspicious activity on board," Spirit Airlines spokesman Stephen Schuler said in a statement.

All passengers were removed from the plane, and after the Transportation Security Administration cleared the plane and luggage, the flight departed for Chicago's O'Hare International Airport - three hours after it was scheduled to leave at 6 a.m., according to Reuters.

One passenger, David Rocca, said that he and fellow passengers were told that security officials would come on the plane and should remain seated, according to a phone interview with the Associated Press.. He went on to say that two men and a woman, along with their luggage, were removed from flight at first, then a officials later returned to remove the the third man.

"They quietly stood up, removed their bags and followed the two officers off the plane," Rocca said.

This incident comes on the heels of the attacks in Paris on Friday that killed 129 people.