Stand-up comedian Dave Chappelle has been attacked by a person who ran on stage at the Hollywood Bowl in LA.
“A man charged and tackled” Chappelle just as the show was ending, according to Brianna Sacks, a reporter at the show.
She said security “rushed and started punching and kicking the s*** out of Chappelle’s attacker”.
Actor Jamie Foxx was among those who tried to help.
Video later showed the attacker, with what appeared to be a dislocated arm, being loaded onto an ambulance.
Another journalist at the show said they had “lunged” at Chappelle and sent him “flying in the air”.
“He fell backwards on to his back, with his arms and legs up in the air. He was obviously in shock. We were all in shock…” said Sharon Carpenter.
Los Angeles Police Department told NBC that the male suspect had been armed with a replica gun that could eject a knife blade when discharged correctly.
It was unclear if the suspect made an attempt to use the weapon.
In a social media clip just after the incident, Chappelle joked about the attacker: “It was a trans man”.
The comedian has been criticised by some for his jokes about the trans community and there was a backlash last year against his Netflix special.
Fellow stand-up comedian Chris Rock – who was slapped by Will Smith at the Oscars – also performed at the show.
“After Chappelle got attacked, he came on stage and they joked that it was Will Smith,” tweeted Brianna Sacks.
Chappelle also spoke about needing more security after his recent controversy, as well as the Chris Rock incident, according to audience members.
UK comedian Jimmy Carr was at the Hollywood show and posted a picture of himself with Chappelle.
“Just happy everyone’s ok,” he tweeted.
The incident happened at the last of Chappelle’s four performances at the venue, part of the Netflix Is A Joke comedy festival taking place around LA.
The 48-year-old later returned to the stage to thank Jamie Foxx for intervening.
“Whenever you’re in trouble Jamie Foxx will show up in a sheriff’s hat,” he joked.
“This man is an absolute genius – we got to make sure we protect him at all times man – this is what it’s about…” Foxx replied.
A Hollywood Bowl spokesperson said “an active investigation” was under way.
Chappelle last year hit out at cancel culture after the backlash to his Netflix special, in which he said “gender is a fact” and declared himself part of “team TERF” – which stands for trans-exclusionary radical feminist.
However, he also said he was willing to discuss his show with members of the transgender community.
The controversy saw some Netflix staff walk out in protest but the streaming giant stood by Chappelle and refused to take down the programme.