South Australia will be in lockdown from 6pm today for at least seven days.

Premier Steven Marshall announced the lockdown at 10.30am this morning, confirming that the local COVID-19 cases diagnosed yesterday are the Delta variant.

Five people have now tested positive to COVID-19, including a diner from the Greek on Halifax restaurant who attended a private function with another diagnosed case.

Under the lockdown people can leave their home for the following reasons:

- to provide essential care for another person

- essential shopping and work

- medical reasons (including getting vaccinated)

- exercise (limited to being carried out with people from the same household).

Schools will be closed, with public school teachers able to get ready tomorrow for online learning from Thursday.

“This is moving very quickly,” said Premier Steven Marshall.

“The reality is we are dealing with a different variant.”

He thanked everyone who had been tested so far and to SA Pathology staff.

Mr Marshall acknowledged that the restrictions will take “a heavy toll” on business but said a short heavy lockdown was the best alternative to “stamp the Delta variant out”.

“The alternative would be catastrophic to our state,” he said.

Chief Public Health Officer Nicola Spurrier urged people to “stay put” in their homes.

She also asked South Australians to keep checking the SA Health website as more exposure sites will continued to be added.

The organisers of the Willunga Almond Blossom Festival had already announced yesterday that the event would be postponed to November.