Mayor Michael Nutter of Philadelphia may be the first Black politician to address “flash mob” attacks that involve majority Black teens rummaging stores and attacking other races.

“You have damaged your own race,” Nutter said to a group of Black teens, the Washington Times reported. “Take those God-darn hoodies down, especially in the summer. Pull your pants up and buy a belt ‘cause no one wants to see your underwear or the crack of your butt.”

The series of flash mob attacks in Philadelphia involve a group of teens who spontaneously assault random people in the tourist locations.

Nutter then continued: “If you walk into somebody’s office with your hair uncombed and a pick in the back, and your shoes untied, and your pants half down, tattoos up and down your arms and on your neck, and you wonder why somebody won’t hire you? They don’t hire you ‘cause you look like you’re crazy.”

In order to slow attacks, Nutter has moved up the curfew for minors to 9 p.m. on the weekend. Police patrols are also sent to certain neighborhoods.

Each time a child is caught in violation of the curfew, the parent will face an increase fine, according to the Washington Times.

Whyatt Mondesire, president of Philadelphia’s chapter of the National Association for the Advancement of Colored People, appreciated Nutter’s comments and said it “took courage.”

“These are majority African-American youths and they need to be called on it,” he said.

Teens use text messaging to organize attacks on bystanders. On July 29, 20 to 30 teens went to Center City at night, then beat and robbed onlookers. One man was hospitalized as he was kicked in the head repeatedly and had a fractured skull.

Philadelphia is not the only city facing the same “flash mob” attacks. During memorial day weekend in Chicago, teens knocked over cyclists and “harassed picnickers,” according to the Washington Times.

In Washington, D.C., 20 teenagers entered a store in Dupont Circle and stole $20,000 worth of merchandise.

Recent flash mob attacks in the U.S. have been compared to riots seen in the current London crisis.