An early morning subway train turned into a nightmare when a rider cried out to a conductor, “I’ve been stabbed!” before losing consciousness, authorities said.

The victim, 32, who later died, was found just after 4 a.m. Saturday aboard a southbound No. 4 train as it pulled into the 14th Street/Union Square station Saturday morning, police said.

There have been no arrests. It’s unclear if the man, who was knifed multiple times, including in the torso, was stabbed on the train or elsewhere.

The conductor called 911 and “officers started performing life saving measures” on the victim, who was later pronounced dead at Bellevue Hospital, police said.

“The conductor was able to talk to him. He said he’s been stabbed but didn’t say anything else,” an NYPD spokesman said.

The spokesman added, “Could he have gotten on the train already having been train or was he stabbed on the train? All of those possibilities are in play.”

The deadly stabbing comes just days after a 36-year-old man was fatally stabbed on a Brooklyn subway train Tuesday night.