South Australia has recorded nine new COVID-19 cases, as it battles its first spike of infections since the Parafield cluster.

All of the new cases are returned travellers quarantining in medi-hotels.

Health authorities said the new cases bring the total number of active cases in the state to 30.

“That’s a really high number. They’re all recent overseas arrivals in our medi-hotels,” Chief Public Health Officer Nicola Spurrier said.

Today’s cases include a teenage girl, a man in his 30s and a woman and three men in their 40s.

There are also two other teenagers and a woman in her 50s who have tested positive, but they are regarded as old infections.

“Out of those nine, three will be classified as historical – they’ve never been diagnosed before — which is why they are still added to our numbers in South Australia,” Professor Spurrier said.

She said the increase had puts her and other health staff “on edge”, and their priority was to protect the state from another outbreak.

She reminded people to continue to take precautions against spreading coronavirus, and called on all eligible people to make efforts to get vaccinated.

The South Australian government has also announced it is allowing Adelaide Oval to return to full capacity from May 8.

That means it will be able to have a full crowd for the AFL Showdown between Adelaide Crows and Port Adelaide.

“Footy fans will be able to go along to the Showdown at the full capacity of the Adelaide Oval,” Premier Steven Marshall said.

“I know that they’ve been waiting for this for a very, very long period of time.”

Professor Spurrier said she was confident “about the safety of the set-up” at the Adelaide Oval, after consulting with the stadium’s management.

Crowds will be required to wear masks when entering of leaving their seats or moving around the stadium.

-more to come