Updated

Four people, including an off-duty police detective and his wife, were taken to a hospital after a "flash mob" attack by some among a crowd of juveniles in downtown Philadelphia, police said.

Police said a large crowd of juveniles were at 16th and Walnut streets, a popular spot for dining and shopping, at about 6 p.m. Saturday when some people began randomly assaulting people on the street.

A 55-year-old off-duty police detective saw a 20-year-old man and a 21-year-old woman being assaulted and tried to arrest one of the offenders. He was punched from behind by several people, police said.

The detective's 53-year-old wife splashed water on the offenders to try to stop them from attacking her husband, and she was punched in the face, police said. All of the offenders then fled.

One of the five people assaulted there declined medical treatment, but the other five were taken to Thomas Jefferson University Hospital for treatment. The police detective had an orbital fracture to his right eye while the others had minor injuries.

Immediately afterward, there was another assault by several juveniles nearby, and two 16-year-old youths were arrested, police said. The victim had minor injuries and didn't seek medical attention.

One man told WPVI-TV that he feared for his safety when the large group of teens appeared, and he saw other people running into nearby stores to escape.

"It's crazy out here," said Dwight Magood. "I don't know if they were trying to protest or 'flash mobbing.' But it's not the right way to do it, whatever it was."