The incidents happened on November 19 at three separate locations near Center City and Logan Square.
In all of the attacks, investigators say the victims were approached from behind and brutally assaulted by seven juveniles.
Police say a 24-year-old woman was walking along 17th and Chestnut streets around 3:20 p.m. when she was pushed to the ground and punched in the head several times without provocation. The woman was taken to an area hospital where she was diagnosed with a concussion.
Twenty-five minutes later, police say the same group assaulted a 31-year-old man on the 200 block of N 19th Street. He suffered irritation and redness to the face and bleeding from his mouth, according to investigators.
Around 4:10 p.m., a 41-year-old woman was walking in the area of 2001 Pennsylvania Avenue when police say the group punched her and pulled her hair before fleeing on foot.
No arrests have been made.
Anyone with information on the juveniles is asked to call police at 215-686-TIPS.