A family is under police investigation assaulting their middle school-age daughter in the middle of downtown Seoul.

Gangnam Police Station said Sunday it had opened an investigation into the girl's parents, in their 40s, and her older brother on respective charges of child abuse and assault against the girl, whose exact age remains undisclosed.

The three allegedly assaulted the victim for about 20 minutes, punching and kicking her on a road near an apartment complex in Gangnam, Seoul, around midnight on May 15. Surveillance camera footage shows the father running after the victim, who is fleeing the scene barefoot, and beginning the assault after catching her. Other family members soon appear and join in. No history of emergency calls to report domestic violence or child abuse within the family had been reported before this incident.

Police booked the parents and the brother at the scene, and three days later on Thursday, banned all family members from approaching or attempting any kind of contact with the victim. The father has been detained in the Eastern Detention Center of Seoul since Friday, as the police applied the strongest temporary measure under the Child Abuse Punishment Act.

During the investigation, the parents reportedly stated they had "asked (the victim) to fill out a preliminary questionnaire for hospital treatment, but the child refused and ran away. The incident happened in the process of running after the child."

The victim is currently staying at a shelter for assault victims, and has been separated from her family.