Crowds fled New York's Penn Station Friday night after an Amtrak police officer deploying a Taser was mistaken for gunshots, causing a stampede that left 16 injured.

NBC New York reported that tourists, commuters and New Yorkers alike were hiding behind garbage cans, diving behind pillars and leaving belongings as they scrambled to escape the calamity. Rumors of a shooter spread to nearby Macy's at Herald Square, where people were seen rushing from the exits. At a press conference Friday night, the FDNY said 16 people were treated for non-life-threatening injuries after the Penn Station stampede. The NYPD said police received dozens of 911 calls to report shots fired at Penn Station, reports that were ultimately unfounded. Tensions were already high at the busy station after power problems caused a NJ Transit train carrying 1,200 passengers to get stuck in a Hudson River tunnel, leading to cancellations and delays for NJ Transit, Amtrak and LIRR trains just a week after a minor derailment led to days of service disruptions.

The stuck train spent three hours in the tunnel before it returned to Penn Station, where six people were treated for minor medical issues, officials said. As people were leaving the train they witnessed what one person described as a "wave of screaming and falling people."

A man near the Amtrak waiting area of the station had become belligerent and Amtrak police used a Taser on him, authorities said. News 4 video shows the man being led away in handcuffs.

The pop of the Taser and the reactions of people nearby spread fear through the Amtrak waiting area. Some people thought there was a shooter and ran. Others followed, unsure why hordes of people were fleeing.

"People were dropping luggage, kids, everybody was just running," one witness said. "Everybody was really scared. It was a stampede."

People were seen crying and screaming as they ran out of the station. Those still inside the waiting area stood around in shock or disbelief as the mayhem began to subside.