A man has been arrested after allegedly threatening members of the public with a large kitchen knife while walking along King William Street in the city on Saturday night.

Police will allege the 26-year-old Adelaide man was walking along the busy thoroughfare and threatening Saturday-night revellers with a knife.

No one was injured in the incident.

Police rushed to the scene and took the man into custody, charging him with threatening unlawful violence.

Video footage on the incident has emerged on social media, showing a man wearing a black shirt, black pants and sneakers walking along King William St while yelling and brandishing a knife.

Other footage shows the moment police swooped on the suspect.

The man can be seen sitting on the footpath with officers surrounding him, one yelling ”police, hands on the ground”.

The suspect then lays face down on the ground and police lurch forward and arrest him.

The man was refused police bail and is set to appear in the Adelaide Magistrates Court on Monday.