CHICAGO >> Police say a gunman standing on a subway platform opened fire on an “L” train in downtown Chicago, though no one was injured.

Chicago Police spokesman Martin Maloney says officers arrested a suspect a short distance away after the Thursday shooting and recovered a weapon.

The shooting occurred at the LaSalle Street Blue Line station, near the Chicago Board of Trade building in the city’s financial district.

John Langston says he was in the first car of the train that was hit. He says four or five shots were fired, and sounded like blows from a sledge hammer. Langston says spent shell casings littered the platform.

Police say the gunman fled after the shooting.

Chicago Transit Authority spokeswoman Catherine Hosinski says passengers were unloaded. No one was reported injured.