A 13-year-old was arrested after he allegedly was part of an attack and robbery of a 76-year-old man in the Bronx, but police are still searching for the other two members of the violent, scooter-riding trio.

The victim was approached by the three suspects on mopeds near Webb Avenue and Sedgwick Avenue in the University Heights neighborhood around 2 a.m. Sunday, according to investigators. One of the suspects punched the victim in the head, causing him to fall to the ground.

After the man fell, the other two suspects went through his pockets and took his cellphone, which they then smashed on the sidewalk, police said.

The trio then drove off on West Fordham Road. The victim was treated at the scene for a cut to the head and is expected to recover.

Police released images of the three alleged attackers (above photo). The identity of the 13-year-old arrested was not released, but police said he was charged with robbery.

An investigation is ongoing. Anyone with information in regard to the alleged attack and robbery is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or on the CrimeStoppers website.