A 29-year-old man was hit on the head with a hammer following a dispute on a northbound J train on Friday evening, the NYPD said.

The argument, involving the 29-year-old, a second 53-year-old male victim and a large group of unidentified suspects, took place about 9:05 p.m. Both victims were kicked and punched by the group before the 29-year-old was struck multiple times with the hammer, police said.

The 29-year-old suffered contusions to the head and was taken to the hospital in serious but stable condition.

The NYPD is looking for four male suspects in connection with the incident who fled the train at the Bowery Street station. The police were unable to describe any remaining individuals who may have been involved. The four suspects are described as being in their 20s.

Police ask anyone with information regarding the incident call the NYPD’s Crime Stoppers Hotline at 800-577-TIPS.