PHILADELPHIA (CBS) –– What started as a weekend barbecue at a recreation center led to an aggressive encounter with Philadelphia police officers.

Around 400 teens in an unauthorized gathering confronted police outside the Lonnie Young Recreation Center in Germantown Sunday night.

Police say it all began after 6 p.m. When officers arrived, they found the large crowd on the sidewalk and in the street, as most were estimated to be between 12 and 17 years old.

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Councilwoman Cindy Bass said the following about the incident Monday: “It is clear that this situation highlights a serious need in the City of Philadelphia. One of the things I hear time and time again from our youth is that they do not have anything to do, especially in the summer. While the City has done a commendable job in providing a wide range of activities and programming, we need to do more. Much more. Could this have been prevented if we had extended recreation center programs into Sunday afternoon/evening? What are we doing to connect our young people to available job opportunities? As both a councilwoman and chair of the committee that oversees the city’s parks and recreation system, it is my job to figure out what we need and how to get resources directed to those that need it the most.”

Officers said glass bottles were thrown at them. Publicly available videos on social media show the teens surrounding officers in their vehicles, hopping on top of cars and generally taunting police.

Myles Nicholson and his friends had the idea to have a barbecue behind the recreation center. It was meant to be something positive for the community.

“There’s nothing out here for us, but to get in trouble,” said Nicholson. “So we were just trying to make something for everybody to come out and have fun and get together. ”

Police commanders made the decision not to make any arrests, as to not escalate the situation, and the crowd disbursed within in few hours.

“There’s no reported injuries to police, no reported arrests, and there’s no reported injuries to civilians at this time,” Capt. Drew Techner with Philadelphia Police said. “We closed the Lonnie Young Rec Center for the night after all of this. We’re concerned all the juveniles may re-gather in the same location that they started out. We for their own safety want them home.”

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However, the crowd never did reassemble. Techner also has a message for those responsible for all the young people gathered in Germantown Sunday night.

“Parents need to be aware that when they’re sending their juveniles out,” Techner said. “I know it’s nice to get the fresh air, and be out with their friends on a summer night. But parents have to be aware of what their kids are doing, who they are with, and what they’re getting involved in. They need to be home at a decent hour.”

The teens that hosted the barbecue say they have learned a few lessons after Sunday’s incident.

They want to have another barbecue, and keep something positive going in the community. This time they’re going to try and do it with the city’s help. They are going to reach out and try and get a permit.

CBS3’s Alicia Nieves and Henry Rosoff contributed to this report.