The number of COVID-19 cases linked to a western Sydney Thai restaurant has risen to 67 while dozens of people and several hospitality venues have been slapped with fines for breaching coronavirus safety measures.

NSW recorded 14 new cases in the 24 hours to 8pm on Saturday including six associated with the Thai Rock Wetherill Park restaurant cluster with two of these also linked to Our Lady of Lebanon Church.

Four cases were associated with a cluster tied to a funeral service at St Brendan's Catholic Church, Bankstown on July 18.

NSW Health says isolation and testing are essential for everyone who attended the morning service, a burial at Rookwood later that day and Mount Pritchard's Our Lady of Mount Carmel the next day, July 19.

Those at a July 16 service at St Brendan's and at a Fairfield funeral home on July 17 must also heed the same advice to "isolate, get tested for COVID-19 regardless of any symptoms, and continue to self-isolate for 14 days even if the test is negative", the health department says.

Three of the new cases recorded were returned travellers in hotel quarantine while one case remains under investigation.

NSW Health later on Sunday urged anyone who attended the Thai Rock restaurant in Potts Point for more than two hours between July 15 and July 25 to get tested and self-isolate for 14 days since they were last there, regardless of symptoms.

The advice comes after a staff member at the restaurant - which has the same owners as Thai Rock in Wetherill Park - tested positive.

It's the second infection linked to the Potts Point restaurant after NSW Health previously announced a case who attended the venue on July 17.

Investigations have not yet identified links between the cases at the two Thai restaurants, NSW Health said in a statement.

Authorities are also urging anyone who attended AN Restaurant in Bankstown on July 23 from 9am to 11am and Tan Viet Noodle House in Cabramatta on July 22 from 1pm to 2pm to monitor for symptoms after the restaurants were exposed to the virus.

Georges River Grammar School in Georges Hall has also been temporarily closed for cleaning after a child who attended the school tested positive. The child is linked with the funeral and church service clusters in southwestern Sydney.

The number of people being treated by NSW Health rose by two to 99. Four remain in intensive care, including one being ventilated.

NSW has now recorded 3479 cases - up 249 in the past 21 days.

Residents have been urged to avoid all non-essential travel and gatherings.

"Of particular concern is transmission in venues such as hotels and restaurants, the gym and social gatherings," the health department said in a statement.

"Consider using a mask in situations where you are unable to social distance, particularly indoors."

Meanwhile, NSW Police have fined 12 people $1000 each after a music event in bushland near Jindabyne on Friday night.

A venue in Thredbo was on Saturday also found to be breaching several safety measures including exceeding capacity limits and the licensee was slapped with two $5000 fines, police said in a statement on Sunday.

A travel company owner who organised for a large number of people to attend the venue was also fined $5000.

Three separate fines have also been issued to hospitality venues in Port Macquarie while four venues in the Illawarra region were fined for failing to comply with the safety orders.

NSW Police said further fines are anticipated for other alleged breaches.