NSW had 10 new cases of COVID-19 on Monday, with Premier Gladys Berejiklian insisting the escalating Sydney CBD virus cluster isn’t out of control.

The 10 coronavirus cases in the 24 hours to 8pm on Sunday came from more than 14,000 tests.

Six infections were in travellers in hotel quarantine and four from the CBD cluster.

The cluster, which has grown to 34 cases, is associated with the City Tattersalls gym in the Sydney CBD.

People who attended the gym between 8am and 2pm on August 19, 21, 23-25 are considered close contacts and must self-isolate and get tested immediately.

“It’s pleasing to know our fears about the CBD cluster have not yet materialised, in that it’s being contained,” Ms Berejiklian said on Monday.

“I’m pleased we’ve got through the winter months as well as we did.”

However, the gym, a Sydney bus route, and a pub have became the latest subjects of urgent public health warnings related to the outbreak.

Commuters who boarded the same Sydney bus as two confirmed COVID-19 cases have been told to self-isolate. Passengers on the X39 bus that left the CBD at 6.08pm on August 20 and arrived in Randwick at 6.40pm are considered close contacts.

There were 14 people on the bus, with 13 traced to date.

Authorities have reviewed CCTV footage and Opal card data to track down the passengers.

NSW Health is urging everyone to wear masks on public transport. Ms Berejiklian is still resisting pressure to make it mandatory.

She said data from Service NSW showed about 60 per cent of people were wearing masks on public transport.

“The health advice says it could give people a false sense of security,” Ms Berejiklian said.

“We don’t want people wearing a mask thinking they can go out and conduct their business if they are infected. It won’t work.”

The NSW Rail, Tram and Bus Union has also said the recommendation for mask use on public transport didn’t go far enough.

“The NSW government recently told bus drivers it would review health advice and guidelines if community infection levels increase,” RTBU secretary David Babineau said on Monday.

“Now it should be clear that health measures are most effective when proactive, not reactive,”

Almost 60 per cent of people agree with wearing masks on public transport. Photo: AAP

NSW Opposition Leader Jodi McKay wants masks to be compulsory on public transport.

“We now have an entire busload of passengers forced to self-isolate. Premier, please bite the bullet and make face masks mandatory on public transport. The dithering has gone on too long,” she tweeted on Monday.

In another alert, people who attended Highfield Caringbah pub for more than two hours from 6-8.30pm on August 22 have been told to isolate and seek testing.

Gym-goers who used Randwick’s Fitness First weights room on August 23 from 3.30-4.15pm have also been directed to self-isolate as close contacts of a known case.

• See all NSW venues of concern here

Meanwhile, Reddam Early Learning Centre at Lindfield has been closed for cleaning after a staff member tested positive, having worked from August 25-27 while infectious.

St Paul’s Catholic College in Greystanes was also shut on Monday for cleaning.

Additional alerts for casual contacts were issued for Woolworths and Chemist Warehouse in Balmain, Sushi Rio in Chatswood and Coles at St Ives on Monday.

Authorities are also investigating the source of an infection acquired by a staff member at the Surry Hills Police Cells Complex.

NSW deputy chief health officer Jeremy McAnulty said the Justice Health and Forensic Mental Health Network were taking appropriate health and safety measures.

NSW Health is treating 66 COVID-19 cases, including six in intensive care.

-with AAP