An uncontrolled bushfire warning for residents near Port Lincoln has tonight been downgraded to a watch and act message, with the Bureau of Meteorology (BOM) saying a cool change is helping to ease conditions.

Key points: An emergency warning for the Duck Ponds fire has been downgraded to a watch and act

An emergency warning for the Duck Ponds fire has been downgraded to a watch and act An evacuation centre is still open at a local bowls club

An evacuation centre is still open at a local bowls club The town's mayor says two people have been hospitalised

Port Lincoln Mayor Brad Flaherty said two people had been hospitalised following the bushfire and some structures had also been damaged.

He said about 280 hectares had been destroyed so far.

Kirton Point Bowling Club, on Cook Street in Port Lincoln, is open as an evacuation centre.

A warning was issued about 4:20pm on Monday for the bushfire at Western Approach Road at Duck Ponds, north-west of Port Lincoln.

The CFS said residents were "in danger" and should "take shelter in a solid building".

"Do not leave or enter this area in a vehicle or on foot. It is too late to leave as the roads will not be safe," the CFS warning said.

"Conditions are dangerous and firefighters are now unable to prevent the fire spreading.

"Shelter before the fire arrives as heat can kill you well before the flames reach you."

It said the stubble fire was uncontrolled and burning in an easterly direction towards Port Lincoln.

The Country Fire Service said residents were "in danger" and should "take shelter in a solid building". ( Robert Lang )

It ordered 10 water bombers to the area to assist 26 grounds crews at the scene.

The warning also stated residents could lose power, water, phone and data connections, but should not expect a firefighter at their door.

SA Power Networks disconnected power to some parts of the township earlier on Monday.

"Due to the rapid escalation of weather and fire conditions we're now disconnecting power to Port Lincoln to ensure community safety," it said in a statement earlier this afternoon.

"We will restore power when safe to do so."

Paul Roberts from SA Power Networks said the conditions had escalated to the point where the power had to be switched off.

"We've seen a really rapid upswing in only a few minutes in the wind speeds in the area, and obviously with a high fire danger index we've taken the decision to disconnect power in the hope we can avoid any issues for people or property," Mr Roberts said.

Mr Roberts said everyone in Port Lincoln and its surrounds would be impacted.

"Unfortunately we've only got a fairly high level switch that we can do, so everyone will lose power in Port Lincoln for the duration of these conditions."

Just before 8:30pm, SA Power Networks said it had restored power to the main district of Port Lincoln and was in the process of restoring power to the northern and western parts of the township to the edge of the fire zone.

Port Lincoln has a population of about 16,000 people.

'Hazy right across the foreshore'

Earlier, Jade from Possums Store in Port Lincoln told the ABC her family had made the decision to evacuate.

"We packed up our five kids and got in the car with our valuables and a change of clothes and just decided to evacuate and keep ourselves safe," she said.

"We just drove down to the foreshore and thought being close to the water was a good idea."

Thick grey clouds billowing from the bushfire covering Port Lincoln. ( Twitter: Tom Rush )

She said the weather had cooled down, but it was still smoky.

"The smell of smoke has increased and it just looks hazy right across the foreshore," she said.

Port Lincoln resident Paul said he was hopeful fire crews would get on top of the fire.

"It's very close. It's only maybe a kilometre across that way, so it's not far. It travels pretty quick. As soon as that wind changes it'll travel pretty quick," he said.

"A little nervous seeing as it's the second time around. But if the wind doesn't change we'll be OK."

Mr Flaherty said the conditions were very similar to the conditions which caused a bushfire in the region in December 2009.

"We've had a bushfire that's burnt in the same fireground as the December 2009 fire. Luckily there wasn't a lot of undergrowth through there," he said.

"We thought we were going to lose houses again. We may have at this stage. We're not sure."

At about 7:30pm, BOM senior forecaster Jon Fisher said winds were continuing to switch around to the south-west.

"Earlier this afternoon we saw the really strong winds from the west to north-west there and that's when the fire started," he said.

The emergency message was tonight downgraded to a watch and act message. ( CFS )

He said the winds gusted up to 70 kph, and with the hot, dry conditions, briefly reached a catastrophic fire danger.

"As those winds turn south-west and become almost southerly [after 7:00pm] we are seeing much cooler conditions develop and more humid conditions.

"With the winds remaining around 40kph, maybe a bit stronger and gustier at times, the risk is still there but in terms of the moisture and the temperature, conditions are gradually improving."

White Hut fire now 'contained'

Firefighters battled several fires across the state, with the CFS advising of another bushfire near Marion Bay Road at White Hut earlier on Monday.

The fire has since been contained and the CFS managed to prevent it from entering the Warrenben Conservation Park.