Chicago police are searching for five or six men or boys suspected of sexually assaulting a 15-year-old girl on Facebook Live.

Department spokesman Anthony Guglielmi said Tuesday that detectives found the girl and reunited her with her family. She went missing on Sunday.

Guglielmi says about 40 people viewed the attack on Facebook while it was happening, and none of them reported it to police.

Police Superintendent Eddie Johnson was leaving a station in the Lawndale neighborhood on Chicago's West Side late Monday afternoon when a woman approached him with photographs of her daughter being sexually assaulted on Facebook, according to Guglielmi.

Johnson immediately ordered an investigation and the department contacted Facebook to take down the video, which it did, Guglielmi said.