The incident happened shortly after 11 p.m. at the South Street police station.
Officers say they heard a disturbance and went outside to find two police vehicles had been damaged.
One vehicle had a hammer sticking out of the windshield.
Raw video: Philly police targeted by vandals on South Street
In addition, police say a firework-style smoke grenade was set off in front of the station, causing a blue stain on the sidewalk, and glass bottles with red paint were thrown at the building.
Investigators say pamphlets with anarchist and anti-police messages were found on the street, along with black gloves and masks.
Police say surveillance video was recovered that shows 10 to 12 suspects wearing all black clothing running from the scene.
Rodrigo Alarcon was walking to his home on South Street and saw the investigation.
"The entire block was cut off. They were escorting all the residents to their houses and the cop mentioned that their windows had been smashed in," Alarcon said.
No officers were injured.
"Thankfully no one was hurt but certainly being targeted at a police station - it does unnerve us," said Captain Sekou Kinebrew.
It unnerves people who live around here, too.
"It's a shame, it's a little bit upsetting. It seems like nowadays people don't like the police. And these are hardworking men and women coming out here to protect us," said Britain Burgos.
Mayor Kenney and members of City Council also released a statement on the incident, "City Council and the Kenney administration condemn in the strongest form violence and destruction of property. What happened to the Police Mini Station in South Philadelphia was illegal and the offenders, when found, will be prosecuted."
Anyone with information about the crime is asked to call 215-686-TIPS. Callers can remain anonymous.
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