A woman was allegedly threatened with a gun, tied up, assaulted and forced into the boot of a car during a violent kidnapping in Adelaide’s northern suburbs, police have said.

The victim called triple zero from the car boot just before 1am on Saturday, claiming she had been kidnapped at gunpoint.

She was able to provide police with vague details of her location, and led patrols to a property at Elizabeth Park.

Police said they found two men and a woman, and the victim tied up in the boot of a Mitsubishi sedan.

Those three people – who were all known to the victim – were arrested, while police are still looking for a fourth man also believed to have a connection to the incident.

The victim was taken to the Lyell McEwin Hospital, where she was treated for injuries including a fractured eye socket.

Police will allege she had met one of the accused at a location at Para Hills earlier in the evening, and was threatened with a gun and forced to drive to the property at Elizabeth Park.

She was allegedly taken inside, assaulted and tied up before being placed in the boot of the car.

Officers found her purse, clothing, jewellery and a replica handgun during a later search of the property.

The arrested trio are a 33-year-old woman from Elizabeth Park, a 33-year-old man from Valley View and a 39-year-old man from Para Hills.

All three have been charged with offences including kidnapping, aggravated threats to kill, aggravated assault causing harm and aggravated assault.

They were refused police bail and will front the Elizabeth Magistrates Court on Monday.

Police are appealing to anyone who may have seen a black Mitsubishi Magna sedan driving erratically, with registration WUA612, to contact Crime Stoppers.

The car is believed to have been travelling through the northern suburbs between 7pm on Friday and 1am on Saturday.

-ABC