A man has driven a car into the front doors of the Adelaide Police Station and threatened officers with a knife.

The Honda sedan was driven into the automated doors of the station on Wakefield Street, just before 1:30am.

Superintendent John De Candia said moments before the incident an unmarked police vehicle had left the complex.

"They heard a large commotion, they immediately returned, at that time the vehicle was reversing out of the Adelaide Police Station," he said.

The man, from Kilkenny, drove into the back of that police car after it was used to block his exit.

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Police allege the man then threatened officers with a small knife.

He said officers used capsicum spray and the man was arrested and taken to the Royal Adelaide Hospital for medical assessment.

"This seems to be an act of criminal damage," Superintendent De Candia said.

"It's unclear at this stage an exact motive as to reasons as to why he's decided to target the Adelaide Police Station and drive through the front doors."

The 38-year-old is expected to be charged with several offences relating to the damage and threats to police later this morning.

No-one was injured and police said the incident was not terrorism related.

The bomb squad had been called in as a precaution and investigations continue.

SA Police said despite damage to the front doors there did not appear to be any structural damage to the building.

The station remains closed and Wakefield Street has re-opened to all traffic.

Security upgrades continue at stations

Police Minister Peter Malinauskas said planned security upgrades at police stations were being done.

He said the police commissioner told him earlier today security upgrades were happening at several police stations.

"Bollards do form part of the upgrade that they're doing generally around at police stations. Of course there'll be some police stations where bollards won't be necessary," he said.

"I understand there's a range of different measures that SAPol are putting in that do include bollards, but also fencing arrangements, security screens within police stations, [and] improved CCTV footage."