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

A brawl in Porirua where a girl was repeatedly kicked in the head is being described as horrific.

Footage of the altercation has been posted on social media showing the girl being set upon by two other people.

READ MORE: Girl hospitalised after being viciously attacked

Police are investigating the incident that happened at Creekfest, a community event in Cannons Creek.

Mayor Mike Tana says it happened at the end of the day in a car park and it seems like those involved knew each other.

He says the altercation is horrific.

"It's horrible when something happens and if it was my daughter that was involved or got hurt, I would be devastated."

He says overall the day had a family atmosphere and spirit about it but he says event processes will be reviewed.

"The way that we spread our people around security, the police will definitely be doing that as well, because this is an event that one incident like this, should not mar and should not stop."