The six girls were arguing with the passenger on the Brooklyn-bound L train about 3:30 p.m. on Dec. 23 when the 28-year-old woman shook her head to "express her displeasure towards the group," police said.
The teens, who can be seen in police video released Thursday, then turned on her, punching her in the face and body and knocking her Samsung cellphone to the floor of the train, police said.
The girls swiped the phone and got off at Sutter Avenue, police said. None of them had been arrested as of Friday morning, according to officials.
The victim got off the train later and used another phone to call 911, police said. She refused medical attention.
Anyone with information should contact Crime Stoppers at (800) 577-TIPS (8477).