Each victim was approached on the street from behind. Three were choked and knocked unconscious. Two were grabbed around the neck and thrown to the ground. None of the women was sexually assaulted.
The attacker then took the victim's purse, wallet or laptop. Three of the women were hospitalized, but none had lasting injuries.
Police have identified a "person of interest" after seeing video from a resident's personal security camera. In the video, taken July 10, the man can be seen throwing away credit cards as he walks down South Perth Street, which is parallel to Seventh and Eighth Streets between Addison and Lombard Streets.
Police say anyone with information should call Central Detectives at 215-686-3093.
Brian Korn, captain of the Sixth District, said he had increased deployment.
"Not only uniformed police cars, but bicycle patrols, plainclothes officers, and officers getting out of the cars and parking and walking," Korn said. "We're also getting additional support from the Third District."
A similar attack occurred Saturday on the 200 block of South Hutchinson Street, where a woman was attacked inside her home, but it has been excluded from the five-case pattern, police said.
The Society Hill Civic Association sends a weekly crime report e-mail to its 1,200 members to alert them of any dangers. Monday, block captains passed out fliers to make sure to inform all 3,500 residents of the assaults.
Rosanne Loesch, the former president of the association, said residents were frustrated.
"This does not happen a lot. That's why everyone is very worried," she said. "It is disturbing. I know a lot of people are talking about it. People are sending out their own e-mails to groups of friends, telling them to be alert, be careful."
Celina Kinane, 54, and her two daughters, Ruth, 23, and Louisa, 25, found out about the attacks Monday afternoon before going out for a walk. They have lived in Society Hill for a year and a half, and are surprised the crime is happening in their area.
"Last week I walked down Spruce and back," Celina Kinane said. "I didn't think about it. The best thing is to not go on our own - two or three of us, it'd be safer."
Louisa Kinane had an idea of who would go with her.
"I'll take my boyfriend with me," she said.
Contact staff writer Alia Conley at 215-854-2917, aconley@philly.com, or @aliaconley on Twitter.