A man was shot and killed after an argument in a Midtown subway station Saturday afternoon turned deadly, police and sources said.

The gunfire erupted inside the 7th Avenue station at 53rd Street, located in tourist-packed Midtown West, at 12:21 p.m., the NYPD said.

First responders administered CPR on the platform before rushing the man to Bellevue Hospital in cardiac arrest, where he was pronounced dead, sources said.

He, the gunman and another individual had engaged in some type of dispute on the northbound platform, though the details are not yet clear, according to NYPD Deputy Chief Keith Shine.

Police have yet to recover a weapon and the NYPD warned that the suspect on the loose is armed and dangerous.

It’s also not clear whether the gunman knew the victim, but police emphasized the shooting was targeted.

"Nothing random between these two individuals," an NYPD spokesperson told The Post at the scene.

An E train had pulled up to the platform and opened its doors just moments before the shooting occurred, with one witness telling The Post he heard two "pops" roughly eight seconds apart, sending straphangers into a frenzy.

“Everybody was running," said Mauricio Marroquin, who was on his way home to Queens after working a morning shift as a breakfast attendant.

"I seen a gentleman laying right in front," Marroquin said of the victim. "He was dressed in a blazer, looked like he was coming from work or something, bro. Going to work or coming from work. It was two shots, man. He only got hit with one, like, that's weird. And they were eight seconds apart, man. That's weird."

Marroquin said several bystanders surrounded the victim, one of whom began chest compressions until EMS arrived and another who held the injured man's hand.

"Another gentleman was just talking to him, like, ‘Hey, man, wake up, wake up, stay up, stay up, stay up,'" said Marroquin.

Harrowing video obtained by The Post shows first responders frantically doing chest compressions on the victim as he lay on the ground of the crowded platform.

Police are searching for the suspect, who was last seen wearing a red tracksuit, black puffer vest and what appeared to be a black balaclava, security footage shows.

The shooting marks the seventh murder in the New York City transit system so far this year.