Madison Beer Stops BottleRock Concert After Shooter Scare from Crowd

Madison Beer cut her mid-day concert short after a gun scare erupted in the crowd beneath her -- which ended with the removal of a guy who's now banned from the premises.

It all went down Saturday evening at the BottleRock festival in Napa, CA -- where Madison was in the middle of performing Radiohead's "Creep," when she abruptly stopped her crooning and ran over to the side stage in a panic after seeing something in the crowd.

In video of the incident, you can hear Madison frantically talking to her stage handlers, saying ... "What is going on? Yo, yo, everyone pay attention. What's going on?!" She then turns to the audience and tells them to back up, seemingly warning them of something happening on the ground.

The video then starts to shake, but it briefly captures what appears to be an older gentleman in a green coat wandering about in an area that seems to be closed off near the front of the stage, with no one else around him. People start to freak out and flee the scene ... reacting to what many perceived as a possible shooter situation.

Further video shows police offers escorting the same guy away in handcuffs.

Napa Police later clarified what exactly had happened, saying cops responded to a disturbance and booted the guy they identified as the responsible party. NPD says no weapons were actually involved, and that there was no active threat to the community.

It's unclear what the guy might've done to scare Madison like that, but whatever it was ... it clearly rattled her and her fans. Madison's mom later posted about it, saying it's sad we live in a world where concert-goers can't enjoy themselves without looking over their shoulder.