The Metropolitan Transit Authority said Dina Saint-Fleur, 25, was arrested after an argument on the J train between her and two of the victims, Princess Llsop, 24 and her boyfriend, Antoine Roddy, 34. Saint-Fleur slashed the victims with a box-cutter, police alleged.
The attack happened on an escalator at the Sutphin Boulevard-Archer Avenue station in Queens, N.Y.
A third man, Andres Nova, 42, was also injured in the incident from an apparent fall on the escalator, CBS News New York reported.
The victims were taken to Jamaica Hospital, officials said. Their status wasn't immediately known.
Trains bypassed the station while police investigated the incident, but service had been restored by about 10:30 a.m., CBS reported.