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."