A man was slashed inside a subway train car in Brownsville Monday evening, prompting an investigation as authorities try to identify the person responsible.

The incident happened just before 7 p.m. on a southbound 3 train while it was at the Junius Street station.

According to police, a 33-year-old man was cut once on the forehead following a dispute with another man on the train. Paramedics responded to the station and took the injured man to Brookdale Hospital for treatment.

The person investigators are trying to speak with is described as a man in his 20s. He was last seen wearing a white shirt and carrying a blue shopping bag.

What led up to the dispute has not been made clear. Investigators are asking anyone with information to come forward.