The Australian police are investigating a shocking video that shows two teenage girls fighting in a park while a group of men were egging them on.

The footage shows a girl wearing a black bikini standing over and shouting at three other young women who were sunbathing in a park in Sydney, Australia on Friday.

The teenager dressed in black then begins punching one of the girls and pulling her hair.

As the violence unfolded, a group of men can be heard encouraging the two girls to hit each other.

The attacker can then be seen dragging one of the women over the grass, losing her bikini top in the process as the victim’s friends try to pull her away.

The attack lasted for nearly a minute and cumulated with the girl in the black bikini launching a final kick at the victim’s head.

A New South Wales Police spokesperson said officers were called to the park at around 2.10pm on Friday afternoon following reports that “a teenage girl had assaulted two other girls”.

They said: “The group dispersed before police arrived. Officers from Eastern Beaches Police Area Command are conducting inquiries.”

The footage was taken by a concerned parent who watched the horror unfold.

“She can’t be let to get away with this thinking she can just attack people and not have any consequence, and the young blokes egging her on should also be tracked down and charged with inciting the violence,” the dad told local media.

It is not clear what provoked the attack.

See the photos of the incident below: