(CNN) -- A police officer shut down an impromptu concert by Switchfoot front man Jon Foreman Sunday night, escorting him away from a group of fans outside a Tampa amphitheatre.
"Just got forcefully removed from my aftershow by the police... Officer Fisher grabbed me by the arm and shut us down. Really?!?," Foreman said in a post to his Twitter account.
Switchfoot played a concert with the Goo Goo Dolls at the 1-800 Ask-Gary Amphitheatre at the Florida State Fairgrounds Sunday.
"Over the years, I've had a few policeman shut these after-shows down. Maybe they are nervous because these types of gatherings are unusual," Foreman said in an e-mail Monday.
"Many times on tour I play after our show when time allows. The after-shows are all about the love of the music -- all acoustic: no amps, no mics, no tickets, just a couple tunes and whoever wants to listen. I see it as a chance to connect with music in a different way."
The crowd showed up when Foreman tweeted to fans, asking them to meet him after the show.
"Aftershow tonight directy [sic] behind the ampitheatre [sic], be there in a 1/2 hour," said Foreman, who included links to a map showing the location and a picture of himself standing on a concrete barrier near the venue.
Video of the incident posted on YouTube shows Foreman playing a couple of songs on an acoustic guitar with a collection of fans around him when the officer walks up and says, "It's over. It's over. C'mon, let's go."
The officer identified himself as "Fisher" when Foreman asked who he was and offered to shake his hand.
After the small crowd mildly protested, asking if one more song could be played, and Foreman hesitated to leave, the officer said, "If I call somebody over here, we will be forcing you out. So what do you want to do?"
The smiling Foreman offered his hand again, which the officer shook, and escorted the singer away.
"Thank you, Jon," several fans shouted as the crowd applauded.
"Thanks for singing along friends! We'll get the cops singing along next time...," Foreman tweeted.
CNN contacted Tampa police, but a spokesman said he was not aware of an incident.
"The officer last night wouldn't give me a reason for shutting it down, he only said that he had a family to go home to," Foreman told CNN. I respect the authorities, they have a difficult job."
The San Diego, California-based Christian alternative rock group is best known for its mainstream hits "Dare You to Move," from "A Walk to Remember" soundtrack and "Meant to Live," which was featured on the U.K. version of the Spiderman 2 soundtrack.
The band won a 1999 Dove Award for Song of the Year for "New Way to Be Human," and earned a Grammy nomination for the album "Learning to Breathe" in the Best Rock Gospel Album category a year later.
"I love playing on the big stages in front of thousands of folks, it feels like a megaphone. It's how I pay the bills and it's the best job in the world. But I also love playing for just a few folks for free. It feels like a whisper." Foreman said of the intimate post-show gatherings he sometimes calls via Twitter.
"It's the chance to dust off the Bob Dylan covers and play new tunes. It's a gift: just to play for the love of the song."