Witnesses said it sounded like an active shooter, triggering mass panic.
"We just hear 'pop, pop, pop...'" said one person. "I thought that somebody just came in and started shooting people."
LISTEN: Audio of sounds that sparked panic in Times Square
"It sounded like gunshots, it definitely did. Two or three thousand people, maybe, just dissipated into thin air," Harlem resident Evan Dore said.
"If I didn't see the motorcycle, it would have definitely sounded like gunfire," said Marvin Tapper, of Las Vegas.
Police said a group of motorcycles was passing through the area of Seventh Avenue and 46th Street just before 10 p.m. when one backfired, sending people stampeding.
"They were all running, like running everywhere. Almost got hit by cars and everything. They jumped out of shoes. There were shoes everywhere," said Ace Guzman, who works in Times Square.
"Hats and shoes, anything, they dropped, they didn't care, just kept going, which you would if you're thinking somebody is about to kill me," tourist Susan Ryan said.
In the chaos, police said 22 people were hurt. Four of them were taken to the hospital with non-life-threatening injuries.
The area was packed with people as Broadway shows let out. Tourist Tara Clauuson was just leaving a theater with her daughters.
"Wanted to protect my children. Safety and praying that this wasn't the end," she said. "We were frightened, because this is the world we live in, and it shouldn't have to be this way. Shouldn't have to have girls with their whole life in front of them be afraid."
"It's a shame the climate of America is like that," said Dore.
Noah Epps, an 11-year-old from Virginia, said he and his parents were walking back to their hotel.
"We just ran as fast as we could. I almost lost my parents," he said. "I had so much adrenaline and I didn't think of anything else, I didn't think of anyone else. Honestly, I just had the fear of losing someone and getting trampled."
"It's the times we live in right now," his father added. "We had the talk last night of what you do in different situations, what is the best way to react, what to do."
Security expert Manny Gomez said the public is being trained to run, hide and ultimately fight in active shooter situations, which made last night especially tough.
"People were kind of sort of doing what we've been saying for a few years now, except that this was a false alarm," he said. "So we don't want to train people not to react."
Gomez added people should feel confident trusting police in these situations, especially if they say things are safe.
Mayor Bill de Blasio took to Twitter to reassure residents, urging anyone who's feeling anxious to contact the city's free, confidential help line.
"Times Square is safe and secure per @NYPDNews. The noises earlier were motorcycles backfiring, not gunshots. But what people felt was all too real. Nobody should have to live in constant fear of gun violence. This country is better than this. Let's FIX this NOW," he tweeted. "These have been disturbing times — and it's normal to feel anxiety right now. Help is available if you need someone to talk to. Call 1-888-NYC-WELL. Trained counselors are standing by."
For more information on the city's NYC Well counseling service, click here.
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