Philly’s struggling with mob violence, and not the kind you’re probably thinking of.

After deading the texting while walking mix-up last month, Philly mayor Michael Nutter has now dropped the hammer on the carnage caused by flash mobs. Recent weeks have seen several Philly residents left with severe injuries as a result of attacks by teens, and Nutter isn’t having it any more.

On Monday, Nutter signed papers that moved the Friday and Saturday curfew up to 9 p.m. for people under 18 in Center City. The curfew throughout the rest of the city remains at 10 p.m. for kids under 13 and midnight for kids under 13. First time offenders will be fined $150 and anyone who makes a habit out of hit can face fines of up to $500.

"I have an understanding of what of our parents are facing, but others are in very challenging situations, and I appreciate that and understand that, but there is no excuse for young people being out so late at night by themselves and then making bad decisions and literally assaulting other citizens," Nutter explained to CNN’s “American Morning” Tuesday.

Nutter did have the foresight to realize that keeping the kids off the streets at night won’t completely solve the issue; it’s giving them something (non-violent) to do that will help. As a result, the city will extend recreation center hours in an effort to give teenagers something constructive to do with their time.

Teenagers hate curfews though, so don’t expect the mob to take this lightly.

[via CNN]