The Police Advisory Commission is investigating allegations that three men were physically abused by police after a show at a South Street venue Sunday night.

Kelvyn Anderson, deputy director of the commission, said four people were interviewed today about the incident, which occurred at the Theater of the Living Arts, 334 South St.

Several bands performed as part of the Bamboozle Road Show and afterward there was an encounter between police and people affiliated with the tour, according to a blog post by Brendan Walter, a member of one of the bands, Valencia.

According to the post, one man was knocked to the ground and beaten with batons by three officers. The man suffered a gash in his head when he fell and hit a bottle. Two others were roughed up, according to the post, and all three were arrested.

A video of part of the incident was posted on YouTube and shows several officers rush inside a door, but what happens inside is not seen. There is a lot of shouting and profanity in the shaky video but no punches or baton strikes are shown.

Police spokesman Lt. Frank Vanore said there have been no official complaints filed to prompt an internal affairs investigation. After watching the four-minute video, Vanore said it is unclear exactly what happened at the scene.

"If a complaint is filed, we will look into it," Vanore said.

Anderson said he was alerted to the incident through Twitter, a microblogging service. Anderson uses a program to watch for mentions of Philadelphia police on Twitter.

It is the commission's first investigation prompted by information from Twitter, Anderson said.

Through Twitter, MySpace and related blogs, word of the incident spread like wildfire.

Travis Clark, of the band We The Kings, posted: "philadelphia was awesome!!! thank you everyone for an amazing show."

His next post an hour later read: "Philadelphia cops just beat us up!"

Several posts later, he vowed: "This won't be ignored, I promise that!"

Clark has 14,600 followers on Twitter. His band has more than 254,000 "friends" on MySpace.