Police are responding to CCTV footage shared on social media that appears to show a security guard being attacked by a group of youths in South Auckland.

Police told 1 NEWS they are yet to pinpoint where the assault took place but the video, which was posted on Facebook yesterday evening, said the incident took place in Mangere.

The video shows a man in a high-vis vest being punched by a youth with no shirt on before more people arrive and chase the man back to his vehicle.

The youths then punch and kick the man's car as he flees the scene.

Counties Manukau West Area Commander Inspector Naila Hassan told 1 NEWS police are making inquiries into the alleged incident and are seeking to establish the circumstances surrounding it.

"This is very concerning behaviour and our prevention teams are currently in the process of identifying those involved.

"We are working with our community and partners to address this type of behaviour and prevent any further instances of this nature. We encourage any members of our community who witness this type of behaviour to contact 111 immediately," Inspector Hassan said.