Firefighters injured in bush blazes

Firefighters hope cooler conditions and some rain overnight will help them consolidate containment lines around two major bushfire outbreaks in South Australia.

Easing winds and reduced temperatures have helped fire crews gain the upper hand in fires at Port Lincoln and Ninga Ninga, near Kingston in the state's southeast.

Five firefighters were injured, mostly through smoke inhalation, nine houses and 11 sheds were lost and the local State Emergency Service centre was destroyed as hundreds of people fled Port Lincoln at the height of the blaze.

More than 850 hectares was burned before the fire was contained.

Thick smoke was also thought responsible for tripping an electrical sub-station, blacking out several thousand homes and other properties.

About 140 Country Fire Service (CFS) firefighters and 35 more from other agencies on the ground at Port Lincoln were being supported by seven water-bombing aircraft including an Ericsson sky crane helicopter.

The Ninga Ninga fire has burned about 1500 hectares of scrub and grassland with 75 CFS firefighters in the area supported by fire-bombing aircraft.

At one stage, three farms were threatened but the CFS said moderating weather conditions had helped crews halt the fire's spread and get the upper hand.

The blaze was thought to have started from a lightning strike.

The fires came as SA sweltered through its worst fire risk day of the summer with eight districts declared at catastrophic risk.

CFS spokeswoman Karina Loxton said rain was expected in South Australia overnight and winds and temperatures had continued to moderate with a cool change.

Fire crews spent the night consolidating containment lines and extinguishing flare-ups, she said, while others used the favourable conditions to get some rest.

- AAP