A woman has been taken into custody as a suspect in the fatal stabbing of a straphanger at a Brooklyn subway station, law enforcement sources told The Post Tuesday.

Police were grilling the 20-year-old suspect, who was picked up early Tuesday and brought to the 73rd Precinct station house, sources said.
Sources said the suspect cut her own hand during the attack, leaving behind a trail of blood.

The victim, identified as 30-year-old Latanya Watson, was in the mezzanine of the Sutter Avenue-Rutland Road train station off the No. 3 line in Brownsville Monday night when she got into a fight with another woman, police said.

The attacker knifed the victim multiple times in the face, neck and arm, cops said.

Medics rushed Watson, who lived less than a half-mile from the train station, to Brookdale Hospital, but she could not be saved.

It was not immediately clear what the dispute between the victim and the suspect was over.