The 48-year-old victim was riding on a B train heading north around 4:20 p.m. on Wednesday, when he met the group of noisy teenagers, believed to be around 16 or 17 years old, police said. As the train was descending the tracks, one of the teenagers stepped on the man’s leg, causing an argument, police said. The group of suspects then punched the rider in the face and arms – and cut him in the forehead with an unknown sharp object, police said. The four culprits got off the train at Cathedral Parkway in Morningside Heights.NYPD The crew got off the train at Cathedral Parkway-110th Street in Morningside Heights, police said. The video released early Friday shows the teenagers, wearing ski masks, leaving the station through the tourniquet. The victim was taken to the BronxCare Health System, where he was treated and released. The incident occurred a few days after a man unprovokedly hit a 37-year-old employee of the MTA booth in Brooklyn. and a week after a 45-year-old woman was cut in the face during an altercation inside a Bronx station, police said.