A bushfire burning on South Australia's Kangaroo Island has been downgraded from an emergency level alert to a watch and act.

The Country Fire Service says it has burned through about 160 hectares.

The crop and shrub fire is burning in a southerly direction towards East West Two Highway.

Authorities warn conditions are continuously changing on Kangaroo Island. ( Facebook: Jared McArdle )

Sixty fire fighters and six aerial bombers are fighting the fire, and the CFS says crews will remain on scene over Sunday night.

Earlier on Sunday, an emergency warning was issued for the fire burning near Harriet Road at Newland, with the CFS saying the blaze was threatening property.

The shrub and crop fire was moving in a south-easterly direction towards the East West Two Highway north of Vivonne Bay.

The fire was being fanned by hot and dry winds and aerial bombers were deployed to the area to help fight the fire.