A dispute on a Midtown Manhattan subway platform ended in a killing on Saturday, when a man was shot once in the chest at the Seventh Avenue and West 53rd Street station, near Times Square, New York police say.

The shooting was reported at about 12:21 p.m. on the northbound E train platform. The victim, a man believed to be in his 30s, was taken to NYC Health + Hospitals/Bellevue, where he was pronounced dead. His identity is being withheld while police notify his family.

Investigators say the argument began on the platform, moved onto a train and then back onto the platform before the shot was fired. Police say the attack was not random, though no motive has been released.

The suspect fled north on Seventh Avenue and is described as wearing a red tracksuit, a black vest and a black face mask and carrying a backpack. No arrest has been made and no weapon has been recovered. The NYPD has released surveillance images and is asking anyone with information to call Crime Stoppers at 1-800-577-TIPS.