An police incident involving a Taser at Penn Station caused mass panic Friday evening as people were spooked by a noise some feared was a gunshot and ran for the exits. 

Amtrak Police had used a Taser to subdue an individual, who is now in custody, Amtrak said in an emailed statement. 

The aftereffects of an earlier disabled New Jersey Transit train, which found hundreds of people trapped in a tunnel mid-afternoon, plus Easter weekend travelers, added to the chaos.

"At about 6:30 tonight we received numerous calls of shots fired in and around Penn Station," NYPD Chief of Manhattan South Bill Morris said in an evening news conference on 34th Street near Seventh Avenue. Morris confirmed that the noise had come from the deployment of a Taser by Amtrak Police. "There were no actual shots fired."

The mass exodus resulted in some 16 people suffering non-life-threatening injuries, FDNY Deputy Chief Tom Currao said.

Erik McIntyre, 29, said he was waiting in the Amtrak area of Penn Station when a man bumped into him as he attempted to flee from Amtrak officers. The man pushed one of the officers and two more officers attempted to restrain him, according to McIntyre, who lives in NYC. 

"He kept fighting back as the officers attempted to stop him," McIntyre said in an emailed interview. "At one point they got pushed up against a pillar and that's when the crowd noticed something was happening."

Michael Clark, 37, was inside Penn Station when he heard what he described as a fizzling sound akin to a sparkler. It was followed by a “massive stampede.” 

"This pack of people ran out to the street,” Clark said, adding that he and many around him abandoned their luggage in the station. Clark returned after about five minutes, he said, when things appeared to have calmed down.

Clark surmised that many people thought the noise was a gunshot, and tweets from inside Penn Station at the time concur.

"I've never heard people scream the way they did when they ran from the scene, though I stayed put because I could tell the situation was under control," McIntyre said, adding that he did not witness any weapon other than the Taser that was used by officers.

The FDNY and emergency medical personnel were already on the scene because of the earlier situation with the disabled train, Currao said. 

"No shots were fired at Penn Station this evening. FDNY is on scene treating injuries that were sustained during panic," Mayor Bill de Blasio tweeted.

Shortly after 7 p.m., the floors of the station remained strewn with pizza slices, spilled sodas and newspapers.