PHILADELPHIA — Mayor Michael A. Nutter, telling marauding black youths “you have damaged your own race,” imposed a tougher curfew Monday in response to the latest “flash mob” — spontaneous groups of teens who attack people at random on the streets of the city’s tourist and fashionable shopping districts.
“Take those God-darn hoodies down, especially in the summer,” Mr. Nutter, the city’s third black mayor, said in an angry lecture aimed at black teens. “Pull your pants up and buy a belt ‘cause no one wants to see your underwear or the crack of your butt.”
“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,” the mayor said. “You have damaged your own race.”
Mr. Nutter announced that he was beefing up police patrols in certain neighborhoods, enlisting volunteers to monitor the streets and moving up the weekend curfew for minors to 9 p.m.
Parents will face increased fines for each time their child is caught violating the curfew.
The head of Philadelphia’s chapter of the National Association for the Advancement of Colored People, J. Whyatt Mondesire, said it “took courage” for Mr. Nutter to deliver the message.
“These are majority African-American youths and they need to be called on it,” Mr. Mondesire said.
Mary Catherine Roper, a spokeswoman for the Philadelphia chapter of the American Civil Liberties Union, said her group sees the curfew move as legal with its sole caveat being that it not evolve “into an excuse to hassle” any youths on the street.
The state ACLU filed a federal lawsuit last year challenging Philadelphia police’s use of “stop and frisk” searches. A settlement announced in June allowed the program to continue, along with safeguards to prevent the use of racial profiling.
In the past two years, the City of Brotherly Love has been the scene of several flash mobs in which youths meet at planned locations by texting one another and then commit assorted mayhem.
In one episode, teens knocked down passers-by on a Center City street and entered an upscale department store where they assaulted shoppers. On another occasion, hundreds of teens gathered in a restaurant district and menaced patrons, forcing some restaurant owners to lock customers inside temporarily for their own protection or to close early.
In the latest event July 29, about 20 to 30 youths descended on Center City after dark, then punched, beat and robbed bystanders. One man was kicked so savagely that he was hospitalized with a fractured skull. Police arrested four people, including an 11-year-old.
Other cities have grappled with the problem of destructive flash mobs. In Chicago on Memorial Day weekend, roving teens flashed gang signs, knocked cyclists off their bikes and harassed picnickers. Police closed a popular beach as the violence escalated.
In January, dozens of young people stormed a popular Milwaukee mall late in the afternoon and scared customers and store employees.
In the District of Columbia, about 20 teenagers entered the G-Star Raw store on Connecticut Avenue at Dupont Circle in April and stole about $20,000 worth of merchandise before fleeing.
The problem has given a heavy dose of bad publicity to Philadelphia, which depends on tourism dollars. At one point last summer, city police stationed four officers at each intersection on weekend nights in a neighborhood where youths had congregated.
Mr. Nutter, a strong ally of President Obama and vice president of the U.S. Conference of Mayors, took to the pulpit of his Baptist church Sunday to deliver a 30-minute sermon about black families taking responsibility for the behavior.
“The Immaculate Conception of our Lord Jesus Christ took place a long time ago, and it didn’t happen here in Philadelphia,” Mr. Nutter said. “So every one of these kids has two parents who were around and participating at the time. They need to be around now.”
The mayor told parents, “If you’re just hanging out out there, maybe you’re sending them a check or bringing some cash by. That’s not being a father. You’re just a human ATM. … And if you’re not providing the guidance and you’re not sending any money, you’re just a sperm donor.”
At City Hall on Monday, the mayor said gangs will be confronted.
“If you want to be aggressive, we’re going to be aggressive,” Mr. Nutter said, before sending a warning.
“Let me just share this with you. We’ve got the biggest, baddest gang in town - a committed group of citizens and a committed government - and we’re working together and we’re not going to have this nonsense anymore.”