Police are looking for a female suspect wanted in a midtown subway train attack that happened in December.

Police say the suspect repeatedly punched a 28-year-old woman while aboard a southbound 6 train as it approached the Grand Central - 42nd Street station on Dec. 22 at about 8:30 a.m.

The victim refused medical attention, police said.

Police on Thursday released a sketch of the suspect, who is believed to be about 5-foot-7-inches and between 25 and 35 years old.

Anyone with information on the suspect is asked to call Crime Stoppers at 800-577-TIPS.