Fourteen of them are linked to previous cases while nine are still under investigation.

Eleven of the 23 cases were in quarantine for their entire infectious period, and 11 were in the community for some of their infectious period.

ACT Chief Minister Andrew Barr said a small number of people had been unknowingly infectious in the community, and urged Canberrans to "please wear a mask".

He said a third of ACT businesses inspected on Tuesday had been found to be operating in breach of public health restrictions. The main issues identified related to staff wearing masks.

Thirteen people are in hospital, and four of them are in intensive care. One is on a ventilator. The youngest is just 18. None of the people in hospital were fully vaccinated.

There were 3763 tests conducted in the territory on Tuesday.

Deputy chief health officer Dr Vanessa Johnston said another 41 people had recovered, meaning there were 256 active COVID-19 cases in the ACT.

Dr Johnston said no new cases had been detected in Ainslie Village residents and the active cases had been relocated from the social housing complex.

Of the new cases, five are associated with the Bright Bees childcare centre cluster, three are connected to the Mirchi Indian Cuisine restaurant and two are connected to the Lyneham High School cluster. Here are the total numbers for each cluster:

Dr Johnston said testing wait times were down and anyone with mild symptoms should get a Covid test, as should those directed by ACT Health.

"What we are doing is working. It is difficult and challenging work, but it's working. We just need to do it for a little longer," she said.

READ MORE:

On Tuesday, the Chief Minister announced an extension of the lockdown to September 17 with some modifications to restrictions.

Schools will continue with remote learning for the rest of term 3 with more information with how schools will proceed in term 4 to be revealed in the first week of the school holidays.

Mr Barr downplayed the chances of Canberrans being able to travel interstate these school holidays, saying he expected other states' borders to remain closed. He was more hopeful for the summer holidays.

He also downplayed the chances of big events returning to the national capital before Christmas.

"I wouldn't be planning a major event this year," he said.

Mr Barr clarified that the new rules starting Friday will permit five people to do non-organised recreational activities, like walking, jogging, cycling and going for a picnic in a park.

"It does not include organised boot camps, sporting competitions, organised team training, golf, tennis, those sorts of more organised sporting activities," Mr Barr said.

Mr Barr said 16,500 Pfizer vaccine bookings had been made on Wednedsay morning after bookings opened for 16- to 29-year-olds.

The 500,000 doses that Prime Minister Scott Morrison announced Australia was swapping with Singapore would effectively bring forward 8344 doses in Canberra. That was the equivalent of a good day of vaccinations, but "every little bit helps".

Under the agreement 500,000 doses are expected to arrive for distribution next week, with Australia to send the same amount to Singapore in December.

MORE COVID-19 NEWS:

Health Minister Rachel Stephen-Smith said people had experienced problems booking their appointments on Wednesday because of an IT problem across the ACT government's systems caused by a power outage, not because of high demand.

Ms Stephen-Smith said the current standard intensive care capacity across public hospitals was 28 beds with a flex capacity of 51 beds and a surge capacity of 110 beds.

Chief Police Officer Neil Gaughan said 26 infringements were issued on Tuesday relating to failing to wear a mask and non-essential travel and that mask-wearing would be the focus of ACT Policing in the next two weeks.

He said 20 people had been charged with failing to adhere to health directions, but the majority were as a result of being charged for more serious crimes such as stealing cars and property theft.

The Chief Police Officer said 20 people attended two anti-lockdown and anti-vaccination protests on Tuesday and that further protest action was expected.

"It does make me angry that people actually want to breach those rules by doing those protests," Deputy Commissioner Gaughan said.

READ MORE:

Our coverage of the health and safety aspects of this outbreak of COVID-19 in the ACT and the lockdown is free for anyone to access. However, we depend on subscription revenue to support our journalism. If you are able, please subscribe here. If you are already a subscriber, thank you for your support. You can also sign up for our newsletters for regular updates.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: