Chicago Police detectives are investigating a viral Facebook video that apparently depicts child pornography, the department told the Chicago Sun-Times Friday night.

Social media users began contacting authorities “regularly” on Friday to report the video, which police said appears, at least, to show a young girl, perhaps 8 years old, performing a sex act on an adult.

An alert about the video frequently started airing over police radio across the city Friday afternoon. Anyone who received or saw the video was advised to delete it and report it to Facebook.

Detectives with the Special Investigations Unit have seen the video and were trying to confirm its authenticity and origin, police said. Facebook and the National Center for Missing and Exploited Children were notified.

On Sunday, Facebook spokeswoman Ruchika Budhraja said in a statement that the social media platform does not allow the sharing of images portraying child exploitation, “even to express outrage.”

“Regardless of intention, sharing such imagery is harmful and illegal,” Budhraja said “When we become aware of such images, we remove them and notify the National Center for Missing and Exploited Children.”

“We urge people never to share such content and to report it to local authorities immediately,” she added.

Budhraja could not provide information about the origin of the video or who posted it to Facebook.