The chaotic scene unfolded around midnight on Market Street near City Hall.
Video recorded at the scene shows fireworks lighting up the sky above the street amid a mass of people and snarled traffic. Apparent street racers were seen drifting in the streets and intersections. One car was recorded doing donuts around a stopped police cruiser while spectators watched.
The next morning, video showed skid marks in the shape of large circles in the street.
Philadelphia police said the department is investigating the incident and looking for members of the group, FOX29 Philadelphia reported.
At least one police car was damaged after people in the crowd jumped on its hood. There were no reports of injuries related to the incident.
“Our number one priority is the safety of the public, which can, and often does become compromised when individuals behave in a reckless manner that endangers themselves and those around them,” a police spokesperson told the station.
Police have yet to make any arrests as of Monday morning.
Investigators said similar incidents were reported over the weekend as unruly crowds continue to be “an ongoing issue within the city,” the station reported. One incident reportedly involved 200 cars.
These types of incidents involving drivers performing stunts in streets or vacant lots are sometimes referred to as “sideshows,” according to the Philadelphia Inquirer, and are often organized on social media.