NSW recorded 13 new COVID-19 cases in the 24 hours to 8pm on Monday with two in hotel quarantine, one a contact of a returned traveller and 10 linked to the Crossroads Hotel in Casula in Sydney's southwest.

NSW chief health officer Dr Kerry Chant on Tuesday said since 8pm an additional seven cases have been reported - all of which were linked to the Casula pub. Another case is under investigation.

Of the 28 COVID-19 cases linked to date to the Crossroads Hotel, 14 are people who attended the pub and the remaining are all contacts of those cases.

NSW Premier Gladys Berejiklian on Tuesday said in response to the outbreak there would be a limit of 300 people regardless of size at indoor pubs and hotels and group bookings would be capped at 10 people.

"It has been apparent to us ... we need to take some further action to curtail some of that high-risk activity," Ms Berejiklian told reporters in Sydney.

"Indoor activity where people aren't seated is a huge health risk because it increases the chance of transmission."

It will be mandatory for pubs and hotels to download and register the COVID-19 safe plan and take down contact details of all patrons.

Venues with a capacity of more than 250 people will be required to have a full-time marshal on site to enforce COVID-19 safety guidelines.

The changes - decided during a meeting of senior government ministers on Monday night - doesn't apply to clubs, restaurants or The Star Casino.

The Queensland Government on Tuesday, meanwhile, declared the Liverpool and Campbelltown local government areas as COVID-19 hotspots.

Residents of those areas who try to enter Queensland will be barred entry, while Queensland-based visitors will be forced into 14 days of hotel quarantine once they return home.

All patrons of the Crossroads Hotel between July 3 to 10 must self-isolate and are being urged to get tested. Investigations are ongoing to determine the source of the infection.

Police are working with Liquor and Gaming to investigate if the hotel breached any guidelines.

One of the cases linked to the Crossroads Hotel is a person who visited the Prestons aged care facility which has now been placed into lockdown.

Dr Chant said there was no evidence the virus had entered the facility but authorities are on high alert.

Another case worked at the Kmart store in Casula Mall and the store has undergone a deep clean. The employee and all of his co-workers are self-isolating.

A case confirmed on Monday that was linked to the venue also visited The Star in Sydney on July 4.

Dr Chant said other venues across Sydney may have been exposed to the virus between June 27 and July 10 after visits from people linked to the outbreak.

These include Picton Hotel, Planet Fitness gym in Casula, Canterbury Leagues Club, Narellan Town Centre and Zone Bowling in Villawood.

Victorian health authorities also on Monday confirmed two residents had tested positive in the southern state after recently travelling to Merimbula on the southern NSW coast.

Australian Associated Press