Thousands of spectators have stampeded in panic at a New York outdoor concert hosted by Hugh Jackman after a collapsed crowd-control barrier sparked fears of a shooting.

About 60,000 people had filled Central Park’s Great Lawn for the politically charged eight-hour Global Citizen Festival, which saw speakers demand an extended investigation of sexual assault allegations against embattled Supreme Court nominee Brett Kavanaugh.

Scary moment at the #GlobalCitizen Festival in NYC, live on @MSNBC: A fence barrier collapsed, the noise was startling, some attendees thought it sounded like gunshots, and there was a stampede. MSNBC cut to commercial, then came back and explained what happened. pic.twitter.com/SumPbM6GC5

— Brian Stelter (@brianstelter) September 30, 2018

Some social media related that concertgoers were screaming that a man with a gun had opened fire.

Several people reportedly suffered non-life threatening injuries in the ensuing crush and commotion.

Big-name politicians and personalities including Democratic New York Governor Andrew Cuomo, Janet Jackson, John Legend and Robert De Niro had spent the day urging spectators to get involved in the nation’s troubled politics and oppose President Donald Trump.

Just ran for my life out of Central Park thinking I could be shot in the back at any moment. I hate that we live in a country where we have to fear this at concerts. a fence falling sounded like gunshots and crowd stampeded out, jumping over fences and hoisting people over walls.

— Cat Quinn (@catquinn) September 30, 2018

Shaken concertgoers draw comfort from each other’s arms after reports of a gunman spooked the crowd. Photo: Twitter/Ciro Gutierrez

Suddenly, just before 8pm, the police barrier that was meant to keep the crowd in check toppled over, releasing a clanging sound that terrified many spectators.

Authorities quickly took the stage, assuring the crowd they were safe and the panic subsided.

Burning social justice issues dominated the eight-hour event that had started on a sunny afternoon. Also scheduled were Cardi B, The Weeknd and other pop stars.

In a video clip, former first lady Michelle Obama urged people to register to vote in the November 6 midterm elections.

Speakers asked the audience to call their Congress members to react to this week’s Senate hearings for Supreme Court nominee Brett Kavanaugh.

“We want equal justice and a full investigation for the Supreme Court nominee, not investigations of limited time, not investigations of limited scope,” Cuomo said.

“And it means before you put a person on the Supreme Court to administer justice, we want to make sure justice is done.”

-with AAP