Port Wakefield Road is closed after a grass fire ignited at Bolivar, north of Adelaide.
The fire, burning in heavy vegetation towards Princes Highway and Paralowie, has now been contained.
About 80 CFS and MFS firefighters with 17 trucks are working on the fireground.
Smoke is visible and the community is urged to avoid this area.
No houses were evacuated, but a Watch and Act message was sent out by CFS.
MFS also contained a grass fire in Port Adelaide shortly after arrival.
The 100 sq m fire on the corner of Perkins Drive and Eastern Parade was extinguished within 20 minutes.