Philadelphia (CNN) -- Despite a stabbing incident involving two teenagers Saturday, Philadelphia Mayor Michael Nutter gave an overall positive review Sunday to the city's early juvenile curfew, which went into effect this weekend.
"We had about 70 curfew violations over the course of Friday and Saturday nights, and I am sure that young people and their parents have now gotten the message," Nutter said.
"We are going to continue to promote the positive, but we will also have continued enforcement of the curfew. It is strict and serious and there are no exceptions," he said.
The stabbing incident occurred after a city-sponsored bowling party, when an 18-year-old man allegedly stabbed a teen-age girl in the arm as she walked home from the event. The suspect has been arrested.
With the newly implemented, beefed-up curfew, city officials hope to quell youth violence and activities by so-called flash mobs.
The new city ordinance mandates a 9 p.m. curfew on Fridays and Saturdays for all minors under 18 in Center City and University City.
On Saturday night, Nutter spent the night bowling with teens at an event planned to give some youths alternatives for entertainment.
"We had a fantastic event last night with hundreds of kids out, bowling, dancing, listening to music and talking to each other. It was a demonstration of what good teenage fun is all about," Nutter said.
The mayor also said he has ordered expanded hours of service at 20 Philadelphia recreation centers on those two nights.
Outside the two special enforcement areas, the normal summer curfew is in effect and children under 13 must be home by 10 p.m. while young people under 18 must be home by midnight, the mayor said.
Nutter announced the earlier curfew following a string of mob attacks by young people alerted to gatherings via e-mail and social media. He signed an order temporarily moving the curfew up an hour on Fridays and Saturdays for everyone under the age of 18 in the two targeted enforcement districts.
"Minors who are caught breaking curfew will be sent home, brought home or transported to a police station where their parents will be contacted. Minors may be issued a citation with a $100 to $300 fine for a first offense," the city said in a news release.
If parents don't come for their child "within a reasonable time, police will contact the Department of Human Services to start an investigation."
Parents will receive a notice for first violations, and will be fined up to $500 for successive violations. They are also subject to imprisonment for up to 90 days for repeat curfew violation offenses, according to the city.
In addition, parents "whose child under the age of 18 is found liable or guilty by a court for injury, theft or other criminal acts" will be liable to the person who suffered the injury or loss of property," the statement said.