As London faces unrest in its communities of color, so too have neighborhoods in the United States.

Ground zero for this problem has been the City of Brotherly Love, Philadelphia.

While the violence has nowhere near as severe as in London, so-called “flash mobs” (groups of teenagers who arrange meetings through social media to jump or rob random people) have left residents uneasy. Images and stories of assaults and acts of vandalism by young, mainly Black, teenagers have been painful for Black Americans nationwide to watch.

It’s also been painful for Philadelphia Mayor Michael Nutter, who has instituted a weekend curfew for teenagers in order to combat the problem. So far, no flash mobs were reported in the first weekend of the new law, but some teens have already been caught violating the rules.

Last Friday night, about 12 teenagers were arrested in Philadelphia after breaking the new 9 p.m. curfew. The teens face up to $300 in fines for their first offense. Under the new rule, parents can be fined up to $500 if their children are caught a second time and can be charged with child neglect if they don’t respond to police requests to collect arrested teenagers.

Nutter recently spoke at a Mount Carmel Baptist Church and spoke out against the flash mobs, which he says are giving Black Philadelphians a bad name.

“You’ve damaged yourself; you’ve damaged another person; you’ve damaged your peers; and, quite frankly, you’ve damaged your race,” said Nutter. He told parents, “Get your act together. Get it together, right now! Or you’re going to find yourself spending some quality time with your kids-in jail, together.”

The city has stepped up programming at youth and recreation centers on weekend nights with the goal of keeping teens off the streets doing something productive.

But that doesn’t mean all was peaceful in the City of Brotherly Love.

A 16-year-old girl was stabbed following a party thrown by the city at the Erie Lanes Bowling Alley. The area had been touted as a teen safe zone.

According to reports, at around 10:20 p.m., the girl and her friends were walking to a nearby bus stop. Police said teens had been released from the event in groups. A male suspect, who had been released in one of earlier groups, tried to talk to her, eventually stabbing her after she ignored him. The girl was treated at St. Christopher’s Hospital for Children and released. The two had known each other prior to the incident.

Other cities might follows Philly’s lead, depending on the success of this early curfew. Kansas City officials have expressed interest in instituting their own form of curfew, but are taking a wait-and-see approach. According to reports, Kansas City Mayor Sly James is keeping his eye on Philadelphia.

“Is it needed? Is it appropriate? Would it work? Those are the questions we’d be asking,” said Danny Rotert, James’ spokesman, to the Kansas City Star.

Kansas City, and perhaps other American cities, may find out soon enough.