In a disturbing event recorded on video, a group of teenage girls allegedly attacked a 12-year-old girl at a bus interchange in western Sydney on Monday night, shouting “bash this slut” during the assault.

Footage captured on a mobile phone at the Mount Druitt bus interchange shows the young girl being knocked to the ground and subjected to repeated kicks to the head by at least four older girls dressed in school uniforms.

In the video, one girl can be heard shouting, “Bash her! Bash this slut!”

A man in an orange high-visibility vest intervenes, helping the victim to her feet and trying to disperse the group.

The victim’s aunt, who wished to remain anonymous, told news.com.au, “They attacked her out of nowhere.”

She explained, “We were just shopping at Westfield and had returned to the station to catch the bus home. Suddenly, a group of high school students approached, singled her out, and attacked her.”

The aunt said her niece had only recently moved to Mount Druitt from Bourke in north-west NSW and did not know the alleged attackers.

She believed the attack may have been sparked by some sort of altercation in the shopping centre.

“Apparently something went on in the Westfield before,” the aunt said.

“She went to the police station and pressed charges but apparently the police are waiting for the Westfield [CCTV] footage.”

Later on Monday evening, a second brawl broke out between the two groups on a suburban street at nearby Lethbridge Park.

The aunt said she and her sister were also assaulted in that incident, which was uploaded to Snapchat.

“The bunch of so-called schoolkids jumped on one bus and we jumped on another bus,” she said.

“We took our niece around for a fair go, one-on-one more or less… bang, they jumped us.”

The aunt said she had reported the second incident to police.

NSW Police confirmed it was investigating the matter.

“About 6:50pm [on Monday], police were called to Mount Druitt bus interchange following reports of an assault,” a spokeswoman said.

“Officers attached to Mount Druitt Police Area Command attended and were told a girl had been assaulted by a number of teenage girls.

“All those involved in the assault had left the scene prior to police arrival.

“About 8 pm, emergency services were called to a home in Blackett, where NSW Ambulance paramedics treated a 12-year-old girl.

“She was taken to Mt Druitt Hospital for treatment.

“Police have commenced inquiries into the circumstances surrounding the incident.

“As inquiries are ongoing, police are aware of multiple incidents involving groups of females across several locations within the Mount Druitt Police Area Command over the past week.

“Investigations are ongoing with police working to establish whether the incidents are connected.

“As inquiries are ongoing, anyone with information is urged to contact Crime Stoppers on 1800 333 000.”