CCTV camera captures the terrifying moment when a man knocked down two partygoers near a beach in San Diego.

The CCTV video, shot on July 8, shows the attacker removing his t-shirt and knocking the two men to the ground with vicious punches in the street fight.

According to the owner of the CCTV video, who has lived locally for the last 15 years, a gunshot then went off at the party taking place nearby, which the attacker returned to after trading blows.

He told Newsflare: "My wife and I were up on our balcony (the camera was next to us). We heard the initial knockdown and went out to see what the commotion was. We ducked back inside when the gunshot rang out.

"It appeared to be a set-up. The two white girls left the party a few moments earlier and stopped the two white guys who happened to be walking by. ... You can see (one of the women) going to him and leaving back to the party with him.

"Another of my cameras has (the two white guys) approaching from the south and minding their own business. I checked earlier video on both cameras and I don't think they had anything to do with the party where the two girls and the black guy came from.

"If you watch into the video a bit, there is another huge black guy who enters the scene from the south and starts challenging the white guys. This guy was unaffiliated with the party, and just came running up when he saw the beatdown.

According to the local resident, this is not an isolated incident but part of a growing trend.

He writes: "This is a reasonably affluent part of the beach and gangs of minorities come to the beach on the weekends and some are here only to raise hell.

"The local police department refers to this area as 'missing beach' due to the high number of thefts and other crime."

+CLIENTS PLEASE NOTE: MUTE FROM SOURCE+

Two girls stop a couple of white guys and start chatting them up. A black guy, who has been at a party on the beach a bit north, surprise attacks and knocks both guys out with some vicious punches.

The first guy down gets back to his feet and wants revenge, but is so "punch drunk" he just staggers into another beatdown.

A passerby helps the second knockout victim until he regains his senses a bit.

At about 2:24, a gunshot goes off at the party that the attacker has returned to (watch as people react and move to cover).

A guy runs into the frame from the north and drops a knapsack on the boardwalk and disappears. (We learned a bit later that he was stashing the gun behind our building.)

This video has had more than 2,400 views on Youtube.