Testing will start at the Watson Neighbourhood Oval as staff move into suburbs of concern for the first time since Canberra started its lockdown almost two months ago.

ACT chief health officer Kerryn Coleman announced the targeted plans on Friday after Canberra recorded 19 new cases.

There have been 30 cases in Watson since the start of the outbreak, and more than half of those have been recorded in the past two weeks.

The biggest concern was that the new cases were not able to be linked to any others in Canberra, prompting health officials to set up a testing site from Saturday morning.

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"We look at the genomics, the epidemiology around the links between people, but we've also been looking at the geographical or the location related links to see if we can see any sort of geographical clustering," Dr Coleman said.

"What we have noticed the last day or two is that we have 30 cases during the outbreak in the Watson area, and almost half of those have been notified in the last two weeks.

"In addition, we're actually unable to confirm the source transmission for some of these cases and as you know, unconfirmed chains of transmission are the major concern for us."

The ACT added 19 new cases to the outbreak on Friday and 13 of those were infectious in the community.

Dr Coleman said there was no common link between the cases in Watson, prompting health authorities to focus on the suburb.

"Just to be clear, I don't know there's a problem," Dr Coleman said.

"We don't know if there's a concerning level of transmission in the community from these cases, but what we do know from NSW and Victoria is that we need to move very quickly to give people the opportunity to get tested so we can understand and detect if there is something we need to do something about.

"We have no public transmission sites, certainly the spread of cases are across Watson, and also come from a number of different backgrounds, including essential workers and other community members.

"When we do this from a geographical perspective, it's kind of the next step in our investigations, to say we can't understand what's going on from all the other information we have.

"Let's try this one and see if we can get to the bottom of it, and interrupt any transmission that's occurring."

Dr Coleman defended the ACT government's decision to delay providing detail about the gradual easing of lockdown restrictions, saying the developing COVID situation would have forced changes to the plan.

"This is an incredibly tricky situation. This is about trying to balance our pathway through the next couple of months as we relax our social restrictions, as we increase our vaccination coverage, and as we work through what our public health requirements of individuals are going to be," Dr Coleman said.

"I don't have the answer for everything, my team doesn't have the answer for everything. What we are doing is working through what we have available to use, the evidence we have available to us in the local context, to provide what we can to people when we can.

"If we went out last week or the week before with some very solid dates, and some very solid examples, I suspect that about half of that would need to change on the basis of our changing outbreak conditions, as well as our changing discussion at the (health committee) as well at national cabinet."

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