Panic set in at the Bonnaroo when Eminem used realistic gunshot sounds in his performance
The rapper was performing his song 'Kill You' at the Tennessee festival when a loud shot rang out from the stage, terrifying many in the crowd.
Video of the incident shows fans having a great time, but when the gunshot sounds there the camera drops quickly and screams are heard.
Warning - the video below contains explicit language.
"Coming from a performing stand point, I get the effect of sound effects on stage, but there's a certain point that crosses the line," one fan tweeted. "I'm one of Eminem's number one fans, but to hear three gun shots coming straight from his set had me scared [as f**k]. Not gonna lie."
"I was having a good time at Eminem's set then he played a realistic gunshot noise," said another. "The whole crowd ducked... completely inappropriate."
The US has a serious gun violence problem, with mass shootings at high schools regularly occurring. Last year, 58 were shot dead and hundreds injured at an outdoor country music show in Las Vegas.
Concerts have also been targeted in other countries in recent years. Twenty-two were killed in Manchester at an Ariana Grande concert in May 2017 by a suicide bomber, and 93 Eagles of Death Metal fans were gunned down in Paris in 2015.
- Ariana Grande concert explosion: Final moments before blast
- Ariana Grande's 'heart is breaking' after Las Vegas attack
- Panic and chaos after Las Vegas shooting
"To hear a gunshot sound effect and see the entire crowd drop to the floor out of instinct is not funny, cute, or amusing," said social media personality Andrea Russett. "This is the sad reality that we are living. This is not funny or even something to be joked about."
While neither Eminem nor Bonnaroo have commented on the controversy, some fans defended the 'Without Me' hitmaker, saying he's been performing the song - with gunshot sounds - since its release in 2000 on The Marshall Mathers LP.
"Women are dancing and singing a song about a man committing domestic violence and brutally killing his wife and y'all upset at sound effects," as one Twitter user put it.
Eminem, real name Marshall Mathers, was sentenced to two years' probation in 2001 after pistol-whipping a man at a night-club. Earlier this year he lashed out at the National Rifle Association, a powerful gun rights lobby group in the US, saying they "love their guns more than our children".