The extended orders follow Queensland's initial three-day lockdown, which had been due to lift on Tuesday afternoon.

The orders apply to travelers returned from 11 Local Government Areas (LGAs) in south-east Queensland.

ACT Health initially said returned travellers had to stay at home until Tuesday, but extended its restrictions in response to Queensland's lockdown extension.

ACT Health Minister Rachel Stephen-Smith said there were more than 2500 people subject to stay-at-home orders in the ACT as a result of Queensland restrictions.

"Queensland has now announced that stay-at-home requirement will be extended until Sunday, the 8th of August. And accordingly the ACT stay-at-home requirement will be extended for that extra period of time," Ms Stephen-Smith said.

The Health Minister said people in the ACT or who had been in the territory and were subject to the orders should make sure they alerted ACT Health of their situation.

"It is really important that we understand that people have actually heard that message and that they are staying at home," she said.

Ms Stephen-Smith said territory health authorities would continue to monitor the situation in Queensland, along with the ongoing outbreak in Greater Sydney.

"We continue to see good news from the surrounding NSW region," she said.

"While we're seeing reasonably high case numbers in Sydney, we're not seeing that seed into regional NSW, and that's a really good thing for us here in the ACT.

"And of course, we continue to have those quarantine requirements in place for Greater Sydney."

There are almost 740 people in quarantine from the Greater Sydney region in the ACT, Ms Stephen-Smith said.

Queensland Chief Health Officer Jeannette Young on Monday said contact tracers needed more time to run down transmission lines at high-risk exposure sites including six schools and public transport routes.

The new cases have all been linked to the existing cluster that began when a 17-year-old student from Indooroopilly State High School tested positive.

One of Monday's cases was active for six days in the community while infectious.

The 11 LGAs impacted include Brisbane City Council, Gold Coast City Council, Ipswich City Council, Lockyer Valley Regional Council, Logan City Council, Moreton Bay Regional Council, Noosa Shire Council, Redland City Council, Scenic Rim Regional Council, Somerset Regional Council, Sunshine Coast Regional Council.

- with AAP

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