Chris Martin calmed the crowd after a barrier collapsed during the Global Citizen Festival on Saturday.
Fans in New York's Central Park had dashed for the exits amid fears a gunman had opened fire on the packed-out audience at around 7.30pm, but the Coldplay frontman reassured them that they were all safe.
He said on stage: "What happened is a barrier fell down.
"Of course it caused people too frightened, but nobody is trying to hurt anybody."
He then invited NYPD Assistant Chief Kathleen O'Reilly on stage to further reassure the crowd.
The officer said: "Everyone relax, calm down. It was a barrier collapse. There were no shots fired."
The 'Viva La Vida' hitmaker then encouraged the audience to head back to the concert.
He quipped: "If you want to come back and you're not too frightened by Hugh Jackman's huge muscles and you wanna come back, this is the time. Slowly, gently, kindly to each other."
Those who had exited the concert were allowed to return, and performances - including slots from The Weeknd and Janet Jackson - continued as normal.
A spokesperson for the event confirmed there had been a "minor incident".
They told E! News: "We did have a minor incident. A barrier collapsed and it made a noise...Police say no cause for alarm."
Meanwhile, Chris' girlfriend, Dakota Johnson, gave out her cell phone number to the entire 60 000-strong crowd to offer support to survivors of sexual assault.
The 'Bad Times at the El Royale' star said: "I want to help you, women and girls around the world, tell your story.
"This is my phone number. I want you to call me and I want you to tell me your story in a voicemail.
"Or I want you to send me a message at [email protected] and I want you to tell me what you've gone through as a woman or girl in the world that's been suffering.
"If we don't speak the same language, that's OK. We have a team for that. "We'll translate it. And if you're going to threaten to hurt me, we have a team for that too.
"I'm sick, I'm repulsed, I'm infuriated by the double standards that continue to threaten women as second-class citizens. Enough."
The concert was staged for charity Global Citizen, which works to combat hunger and poverty around the world. Other performers included John Legend, Shawn Mendes, and Cardi B.