The National Human Rights Commission of Korea (NHRCK) said Wednesday that it has decided to conduct an investigation into a group assault by four middle school students of a girl originally from Mongolia.

It was presented to the commission earlier this month that four Korean female middle school students assaulted a classmate from Mongolia in Yangsan, South Gyeongsang Province, in July. The incident became widely known as a video of the assault went viral when the assaulters allegedly distributed it among their fellow students.

They four girls allegedly tied the victim’s hands and legs and beat her head and slapped her face repeatedly over the course of six hours. They also wrote a racist message on her forehead. The victim moved to Korea more than 10 years ago with her parents.

A petition was posted on the Cheong Wa Dae website, calling for stern punishment of the four offenders, and it has garnered over 220,000 signatures as of 2 p.m. Wednesday.