Queensland has declared the city of Adelaide a COVID-19 hotspot following the emergence of a new cluster of cases overnight.

Seventeen infections have been linked to the cluster in Adelaide’s north.

Queensland Premier Annastacia Palaszczuk announced today that anyone arriving from Adelaide after 11:59pm tonight will have to go into mandatory hotel quarantine for 14 days at their own expense.

Anyone already in Queensland who’s been to Adelaide in the past seven days is urged to immediately get tested and self-quarantine in their own accommodation, even if they don't have symptoms, until it has been 14 days since they left Adelaide.

“I think everyone acknowledges in Queensland we have had extraordinary success rates and the last thing we want to see is Queenslanders having to go into any form of lockdown,” Premier Annastacia Palaszczuk said.

“We do really hope that Adelaide gets on top of that very, very quickly.”

Queensland Chief Health Officer Jeannette Young said it was a rapidly changing situation.

“That’s a very rapid increase in cases from four to 17 (overnight) and some of these cases I understand have been in complex situations, one in a prison for instance, there has been a school involved,” she said.

“So, we need to get more information about where the risks are.”

Dr Young said people who have arrived from Adelaide since last Monday should still self-isolate for 14 days even if their test results come back negative.

“I think it’s unlikely that virus was circulating prior to last Monday,” she said.

Victoria, WA, Tasmania and the NT have all declared Adelaide a COVID-19 hotspot.