"This is a parental issue. This is not a police issue, this is not a city issue. The parents should be watching their kids."
PHILADELPHIA (WPVI) -- A Philadelphia police officer was injured and four teenagers were cited for disorderly conduct after a crowd of hundreds of juveniles swarmed Center City on Wednesday night.
In a Thursday afternoon press conference, Inspector Ray Evers said officers started noticing a larger-than-usual crowd gathering on Market Street East around 6 p.m.
Then, around 7 p.m., a 13-year-old male was seen with a pistol. The teen was chased down and stopped, and Evers said that the pistol turned out to be an Airsoft gun.
Around 7:30 p.m. the crowd swelled to between 350 and 400 juveniles as officers called in more support.
Evers said police then started working to move the teens out of the area.
"We call it a push. We want them basically to get back on SEPTA and go back home," Evers said.
It took until about 9 p.m. to get the juveniles off the street, he said.
The four teens cited for disorderly conduct include a 13-year-old male, a 13-year-old female, a 15-year-old male and a 17-year-old male.
"Our belief is that these juveniles were not here to go to the movies or go to the mall. They were here to be disorderly," Evers said.
An officer was injured when someone tried to let the 13-year-old female out of a police car, according to Evers. The officer gave chase and seriously injured his knee.
That officer will be out for approximately eight to 12 months for full knee reconstruction, Evers said.
The inspector said parents bear some responsibility for what happened.
"This is a parental issue," Evers said. "We have 170 rec centers in the city, we have 26 PAL centers in the city, and we have numerous sports leagues and church groups in the city. This is what the kids should be doing. This is a parental issue. This is not a police issue, this is not a city issue. The parents should be watching their kids, what they're doing."
Also during the incident, a suspect wanted for a robbery at 2nd and Chestnut the night before was taken into custody.
Action News spoke to witnesses who watched the unruly crowd go by.
"I just got off the bus, I saw literally a whole swarm of kids coming up," recounted Brandon Sudan of Atlantic City.
"When we were eating dinner there was a lot of kids. You could see running up and down the street, and whatever, and then we went into CVS. We saw the whole street covered," said Caryn O'Neill, a Philadelphia native now visiting from North Carolina.
There's concern that, with it being spring break and summer on the way, there could be more incidents.
"The other day I was leaving work and there was children blocking both sides, all these cops came everywhere and you do worry - like, what's going to happen?" said Jessica Diaz of North Philadelphia.
Investigators tell us they know the kids are using SEPTA to get around and social media to spread the word.
Police are collaborating with SEPTA to better track large groups while looking for ways to enhance social media monitoring.
We're told to expect increased patrols this Easter weekend.