Facebook has taken down the video, but declined to comment on the alleged assault (Representational)

A 15-year-old girl was allegedly sexually assaulted by multiple suspects, according to Chicago police.The incident was steamed on Facebook Live, according to the victim's family, where police say it was viewed by dozens of people in real time.Chicago Police spokesman Anthony Guglielmi tweeted Tuesday that police are "making good progress identifying persons of interest" in the assault on the teenager, which involved as many as five or six men or boys. The tweet mentioned that interviews are "ongoing" but police have yet to name any formal suspects or make any arrests."What's even more disturbing, more than the fact that they did this, there were so many people that saw this and they didn't pick up the phone and dial 911," police superintendent Eddie Johnson told WGN-TV. "That's just not right and [we're] working on it and try to bring it to a successful resolution."Police told The Washington Post that the teen's family reported her missing Sunday. Family members told WGN-TV that the teenager had gone to the store Sunday afternoon and was later spotted by loved ones on the live feed being assaulted by several males."I just want her home," her mother told the station Monday. "I just want to make sure she's okay cause I know she's probably scared and embarrassed. I just want her back home."Police spokesman Guglielmi told the Associated Press that police found out about the alleged assault after the teen's mother intercepted police superintendent Johnson Monday afternoon as he was leaving a local department on the city's West Side. The mother told the superintendent about her daughter's disappearance and showed him screen grabs of the alleged assault, the AP reported.According to the AP, "[Guglielmi] said Johnson immediately ordered detectives to investigate and the department asked Facebook to take down the video, which it did." He also told the AP that "Johnson was 'visibly upset' after he watched the video, both by its content and the fact that there were '40 or so live viewers and no one thought to call authorities.'"Police said the teenager was located Monday and transported to a hospital in stable condition before being reunited with her family. The incident is now being investigated as a "criminal sexual assault." Guglielmi told the AP that the victim informed investigators that she knows at least one of individuals who allegedly assaulted her.The Post typically does not identify victims of sexual violence.A Facebook spokesman told The Post that the company has taken down the video, but declined to comment directly on the alleged assault."Crimes like this are hideous and we do not allow that kind of content on Facebook," the spokesman said. "We take our responsibility to keep people safe on Facebook very seriously and will remove videos that depict sexual assault and are shared to glorify violence."He said the vast majority of Facebook Live users post responsible content online, but the company tries to interrupt streams that violate Facebook's community standards "as quickly as possible when they're reported to us."The company has teams that work "around the clock to review content that is being reported by users," the spokesman noted.Earlier this year, the social media giant was criticized for taking two weeks to remove a video that showed a 12-year-old girl live-streaming her suicide, according to media reports.Last July, Facebook acknowledged that while live video can be a powerful tool to document events, sharing - and allowing - videos on the platform must be done responsibly. But what has often surfaced is jarring and, sometimes, graphic content.Most recently, a group of four people used Facebook Live to broadcast themselves torturing and taunting a mentally disabled teenager. Last August, law enforcement officials successfully petitioned Facebook to disable the social-media accounts of Korryn Gaines, who was live-streaming her armed standoff with Baltimore County police.

In October, the social media giant announced that it will begin considering the newsworthiness and public interest of difficult or graphic content before censoring it - even when it violates the site's rules. According to its policy, Facebook does not allow self-injury or suicide.