Two dead, two injured in SA car rollover

Two people from Western Australia have died after their four-wheel-drive rolled in South Australia's mid-north.

The 26-year-old driver and an 18-year-old female passenger died when he lost control of his car on the Augusta Highway early on Thursday morning.

Two other passengers, a 20-year-old man and a 24-year-old man, were also injured in the crash and were airlifted to the Royal Adelaide Hospital with non-life-threatening injuries.

Police said efforts were still being made to contact relatives of the deceased in WA.

The deaths bring the state's road toll for 2017 to 38, compared to 39 at the same time last year.