NYPD officers responded to reports of a fire just before 7:30 a.m. at the Coney Island-Stillwell Ave. subway station and found the woman on fire while sitting on an idling F train, police told The Post.

Police extinguished the fire and EMS declared the woman dead at the scene, police said. According to sources, she was found with liquor bottles surrounding her and a box of matches.

It was not yet clear whether she set herself on fire, or if there was someone else involved, sources said.

Police said the incident is under investigation, with the office of the chief medical examiner set to determine the cause of death.