CHICAGO (AP) — Three teenage girls were charged Thursday in Chicago in the beating of a 15-year-old special needs girl that was recorded on cellphone video and shared online, police said.

Two of the girls were charged with aggravated battery and one with mob action, Lt. Ozzie Valdez told reporters. The girls are 13, 14 and 15, and they were charged as juveniles. The charges are felonies.

“The hate that we all saw is an affront to who we are as Chicagoans,” police Superintendent Eddie Johnson said, referring to the video that shows people beating the girl as she screams.

“Actions depicted in the video are difficult to watch, to say the least,” Johnson said. “And I hope that they become a teachable moment, for not only these young individuals but actually for all of us. Hate, bullying and bigotry are cancers of our society that do nothing but break and divide us.”

In the video, the girl waves her arms as she tries to fend off her attackers. The video was posted by someone who described herself in the caption as a friend of the girl, who she said has a “mental disability.”

Police said other people could face charges.

The girl, whose name has not been released, had been missing from her South Side home several days before the attack occurred Monday. She was found Tuesday evening. She was taken to a hospital where she was treated before being released.

“In their interviews the detectives learned that the victim met several juveniles who she thought were her friends,” Valdez said. “These girls then taught her how to flash gang signs and as this was occurring a beating began which was captured on video.”

The three girls were arrested after going with their parents to police Wednesday night.

One was released to her mother Thursday, but ordered to be placed on electronic monitoring, the Chicago Sun-Times reported.  A second girl also was ordered on electronic monitoring and placed at a temporary juvenile shelter.