Two teenagers have admitted inflicting actual bodily harm on a 15-year-old black girl outside a school in an assault that was filmed and went viral online.

The 16-year-old girls, who cannot legally be named due to their age, both pleaded guilty to one count of assault occasioning actual bodily harm on the youngster outside Thomas Knyvett College in Ashford, Surrey, on February 6.

One defendant also pleaded guilty to assaulting a second teenage girl by beating on the same day.

The second defendant also pleaded not guilty to racially aggravated assault occasioning actual bodily harm on that day and sending a threatening message to the black girl on Snapchat two days before.

Appearing at Guildford Youth Court on Wednesday afternoon, they spoke only to confirm their names, dates of birth and addresses before entering their pleas.

Magistrates were shown video of the assault which showed a black pupil being punched, kicked and having her hair pulled while her attackers were egged on by adults.

The second defendant is alleged to have repeatedly called the girl a “monkey” and said they were going to “rip a dreadlock out of your big fat head” in the Snapchat video.

She denies that she was the one making the threats.

Prosecutor Amanda Burrows said the teenager who admitted both charges she faced was being “encouraged to get involved” after she pulled back but was “certainly involved” at the beginning.

Video showed that the defendant was told “get on her” and “that’s it, that’s it” by an adult.

The second victim said in an impact statement that she saw the same defendant assault the first victim while her co-defendant hit her, kicked her in the neck and pulled her hair out.

The girl also said one defendant dragged her onto the floor and kicked her in the thighs for around five minutes while she was on the floor.

The black pupil did not provide a victim impact statement but pictures shown in court revealed her braided hair had been pulled out at the scalp and her eyes were bruised.

The response of staff led to a backlash and criticism by MPs and a protest was held outside the school two days after the attack happened.

Chairwoman of the bench Sue Hodnett bailed the defendant who admitted all charges until she is sentenced at the same court on November 22.

The other defendant, who was also bailed, will stand trial on a date to be fixed and be sentenced for the offence she admitted later.