Police will allege just before 2am on Tuesday 19 April, the accused entered a convenience store on the corner of Hindley Street and Morphett Street and threatened staff with a machete.

He demanded cash but left empty handed.

He then approached a man on Hindley Street and struck him with the machete.

Patrols were quickly on scene and police arrested the accused after a short foot chase.

A 17-year-old from Welland has been charged with attempted aggravated robbery and aggravated assault cause harm. He has been refused bail and will appear in the Adelaide Youth Court later today.

The victim was treated at hospital for cuts to his ear and forearm.