Man arrested over Adelaide carjacking

A man who allegedly threatened a driver with a knife during a carjacking in Adelaide has been nabbed after police posted the stolen car's details on social media.

The driver was about to get into his car in Seacombe Gardens on Monday night when he was threatened by a man with a knife, police said.

A 26-year-old man was arrested hours later in Tailem Bend later after police posted the stolen car's details on social media and someone reported seeing it nearby.

The man will appear in Murray Bridge Magistrates Court on Tuesday.