Twenty to 30 teenagers and young adults beat up a homeless man inside the Columbus Circle subway station Saturday night, leaving him hospitalized with cuts and bruises, police said.

The 28-year-old man was on the northbound A train platform inside the station just after 9 p.m., when the suspects, ranging in age from 15 to their early 20s, attacked him, a police spokesman said. 

The group didn't know the victim, police said, but they couldn't say what started the fight or whether it began on the train.

The man was transported to Mount Sinai West with a cut to his head, swelling and bruising in both of his eyes, and a broken tooth, according to the NYPD.

Sita Cisse and Justin Moore, both 16 and from Manhattan, were charged with gang assault, resisting arrest, obstructing government administration, assault with intent to cause physical injury, unlawful assembly and disorderly conduct, police said.

The investigation is ongoing.

With Nicole Brown and Lauren Cook