The New York City Police Department is searching Thursday for a group of suspects investigators say are wanted for the "gang assault" of a 50-year-old man at a subway station in Brooklyn. 

The "unprovoked" attack happened on Friday, June 2 around 9:45 p.m., police said in a statement to Fox News Digital. 

"The victim, a 50-year-old male, was standing on the mezzanine level of the Stillwell Avenue – Coney Island subway station when, unprovoked, he was approached by a group of unknown individuals who punched and kicked the victim about the head and body before fleeing the station on foot," the NYPD said. "The victim was removed by EMS to NYU Hospital Brooklyn in serious but stable condition." 

Footage released by investigators showed the suspects walking away from the subway station. 

WOMAN SHOVED INTO TRAIN, MAN SLASHED DURING VIOLENT WEEKEND ON NYC SUBWAYS 

At one point, an individual can be seen attempting to do a backflip, but failing. 

The motive for the alleged attack is not clear. 

The incident follows a series of reported attacks in the New York City subway in May. 

In one case on May 19, police said a 33-year-old victim reported that he was riding the southbound D train in Manhattan when he noticed another individual aboard the train acting erratically, according to a report from WABC. 

The victim said the erratic individual then approached him unprovoked and "slashed" him on the chin with an unknown sharp object. 

VICTIM PARALYZED BY NYC SUBWAY STABBING DIES A YEAR LATER 

The suspect then fled when the train stopped at 53rd Street and Seventh Avenue.

"The victim was transported to Bellevue Hospital and was reportedly in stable condition. There are no arrests and the investigation remains ongoing," an NYPD spokesperson told Fox News Digital at the time. "The individual is described as a male, approximately 20 to 25 years of age, dark complexion, 5’7" and last seen wearing a gray hooded sweatshirt." 

In another incident two days later, a 42-year-old woman was transported to Cornell Hospital after she was shoved into the side of a standing subway car in Manhattan, according to a report from the New York Post.

The suspect reportedly fled from the station in an unknown direction, police said, while what provoked the assault remains unknown. 

The incidents come as crime on city subways has gained renewed attention amid the controversial death of Jordan Neely, who was acting erratically and threatening passengers on a train earlier this month before he was confronted and placed in a chokehold by Marine veteran Daniel Penny. 

Fox News’ Michael Lee contributed to this report.