Police are searching for a gunman after a man was shot and killed inside the 170th Street subway station in Concourse Village on Tuesday afternoon — the second shooting reported at the station this year, according to the NYPD.

The shooting unfolded just after 3 p.m. as commuters waited for trains. Witnesses say the sound of gunfire echoed through the station, partially drowned out by passing trains.

“I was listening to my AirPods until I heard someone say, ‘Yo, look at that,’” said Anderson Moinacruz, who was standing on the opposite platform at the time. “Then I saw the person lying there.”

First responders rushed the 41-year-old victim to the hospital, where he later died from his injuries, police said. Witnesses say the shooting followed an aggressive altercation between the victim and the gunman, though the motive remains unclear.

Moments after the shooting, police converged on a nearby apartment building on Townsend Avenue — just two blocks from the subway station — after developing information that the suspect may have been inside. Officers in tactical gear surrounded the building at 1505 Townsend Ave., brought in K-9 units and shut down nearby streets as a precaution.

The heavy police presence disrupted traffic and delayed school dismissals at nearby day cares.

“I’m just a little nervous right now because I want my son,” said Sheena Griffin, whose 4-year-old autistic child was inside a nearby day care during the lockdown. “If your mom is always there on time, he’s expecting me.”

Officers later helped reunite Griffin with her son as the police operation continued.

By early evening, emergency service units completed their sweep of the building. Sources at the scene said investigators no longer believe the suspect is inside, but the search for the gunman remains active.

The NYPD is asking anyone with information to come forward as detectives continue working to identify and locate the suspect.