SYDNEY -- The Australian state of New South Wales (NSW) recorded on Friday a new high in daily increase of COVID-19 cases, raising questions around the effectiveness of Sydney's current lockdown.

The state recorded 31 locally acquired cases in the 24 hours to 8:00 p.m. Thursday, highest single-day increase since June 16 when the index case was detected, bringing the total number of the latest outbreak to 226.

The growth of local cases also came with an increasing number of tests, as a record of 73,602 tests reported to 8:00 p.m. Thursday night, compared with the previous day's total of 59,941.

NSW Premier Gladys Berejiklian said the case numbers reflected a "lag" from the days before entering into lockdown. She expressed her concern over 13 cases that were active in the community while infectious.

"Last night's figure of 13 is concerning, and that is something that we are working to address by stressing to the community: stay at home means stay at home."

"We are anticipating there could be an increase in numbers over the next few days, then hopefully early next week we should see the impact of the lockdown really turning and having a positive impact," she said.

Chief health officer for NSW Kerry Chant did not comment on the potential for Sydney's lockdown being extended.

"I am not commenting at all about the future settings. What I can say is that the factors we consider closely is those infectious days in the community," she said.

Chant said due to the lockdown, contact tracers were seeing a shift in the venues of concern from hospitality venues, beauticians and hairdressers to retail settings.

"Please don't go out and about shopping in retail, in any setting if you have got symptoms," she said.

Meanwhile, the neighboring state of Queensland announced on Friday that it would extend its snap lockdown for another 24 hours until 6:00 p.m. Saturday for both Brisbane and the Moreton Bay Region to its north.

The announcement came as Queensland detected three new cases that had spent time in the Brisbane community.

"This additional 24 hours is essential to give our contact tracers time to identify close and casual contacts," said Queensland's Chief Health Officer Jeannette Young.

"We need to do this to continue limiting any potential spread and keep our community safe."