Warning: The following article contains images that some people may find upsetting.

Shocking footage has emerged of a teenage girl being punched to the ground and kicked repeatedly in the head during a fight at a community festival in Porirua.

In footage posted to social media, a young girl was set upon by two alleged attackers after what appears to be an altercation at Creekfest on Saturday.

The victim was punched in the head by two attackers before falling to the ground where she lay defenceless.

While on the ground, one of the alleged attackers is seen kicking the victim in the head at least five times before launching into a flurry of punches.

Police say they are aware of the footage and are investigating.

According to a family member of the victim, the young teen was left unconscious and bleeding before being taken to hospital.

A woman who posted the disturbing footage on social media said the brawl was "f**king disgusting" and that the day will come where someone dies.

The defenceless girl was kicked in the head at least five times. (Photo / Facebook)

"Sorry to the victims in these videos and their families but I needed to put these up to show everyone what is happening in our streets and not far from our homes," the woman wrote on Facebook.

"These kids are getting out of hand. And this is only one of many MANY incidents were they have bullied another person. This is f**king disgusting.

"The poor girl on the video isn't even fighting back and they are constantly booting her in the head.. what is it going to take for this shit to stop someone dying? Families taking matters into their own hands? It will never end!!

"We need to act on this s**t!!"

A group of girls attacked a defenceless teen during the Creekfest festival in Porirua over the weekend. (Photo / Facebook)

Porirua police say they are deeply disappointed by violence at Creekfest, a Cannons Creek community event on Saturday.

"A video on social media shows a disgusting act of violence toward a young woman at this family-friendly event, attended by about 32,000 people," Kapiti Mana Police Area Prevention Manager Senior Sergeant Grant Ferguson said.

"The organisers worked very hard to produce a quality day and stay true to the anti-violence, healthy living and family theme. I know I speak for the organisers, sponsors and supporters of Creekfest when I say I am deeply disappointed and saddened by what occurred. This is not what the day was about, and not what or how we want people to remember Creekfest.

"The response to the video on social media strongly condemns the actions of those involved. It's encouraging to know more and more people do not and will not accept violence in our communities."

Police attended the incident on Saturday and have launched an investigation.

"We are moving this investigation quickly, to hold those involved to account, in a timely manner. Support has been provided to the victim by police and support agencies," Senior Sergeant Ferguson says.

Porirua's Creekfest 2018 was headlined by singer Stan Walker.

It is described as a family event that raises awareness of health and wellbeing services in the region and has been running since 2004.