Fourth person arrested over Elizabeth shopping centre stabbing

A fourth person has been arrested over last week's violent stabbing in which two people suffered "life-threatening" and "critical" injuries at a suburban Adelaide shopping centre.

The Elizabeth City Centre was placed in lockdown with shoppers evacuated on Friday afternoon after what police alleged was a fight between a group of males.

A 16-year-old boy was stabbed in the leg and a 20-year-old man had a stab wound to his abdomen.

On Wednesday, detectives attended an address at Davoren Park and charged a 17-year-old boy with aggravated assault, aggravated affray and possession of a prohibited weapon.

He has been granted police bail to face the Elizabeth Magistrates Court in January.

His arrest followed the court appearances of two teenage boys earlier this week, a 16-year-old from Elizabeth Downs charged with affray and two counts of causing serious harm, and a 17-year-old from Craigmore charged with aggravated assault and affray.

In the Adelaide Youth Court on Monday, a prosecutor told the court that an application to have the matter moved to an adult court would "likely be considered" because one of the accused teenagers was "two weeks shy of his 18th birthday".

Police on Monday also arrested and charged an 18-year-old man from Paralowie with aggravated assault and aggravated affray.

He was given police bail and was expected to appear in the Elizabeth Magistrates Court next month.

Police said the people involved were known to each other and the incident was not random.

They ask any witnesses or anyone who has mobile phone footage of the incident to contact Crime Stoppers.