Residents evacuated as fire 'six stories high' threatens homes in Adelaide

Residents have been evacuated after a fire came dangerously close to homes in Walkley Heights, in Adelaide's north. 

The fire broke out in a reserve about 3.45pm, with residents on Tower Court and Magazine Drive asked to leave as flames came within metres of properties.

The fire also threatened the Yatala Labour Prison and burnt about three hectares of land. 

One local told 9NEWS the flames appeared to be about "six stories high" at the peak of the fire's intensity.

Witnesses reported seeing youths near where the fire started and police say the blaze may have been deliberately lit.

One firefighter had to be treated by paramedics after being overcome by the heat.