NSW has recorded 13 new COVID-19 cases as three Newcastle pubs and a drug court in nearby Toronto have shut for cleaning after people from Sydney visited while infectious.

Premier Gladys Berejiklian said on Monday the 13 infections were recorded in the 24 hours to 8pm on Sunday, three in returned travellers from overseas and one had been to Victoria.

Eight people remain in intensive care in NSW.

“No matter how tough you are, borders aren’t impenetrable. Unfortunately people always try to do the wrong thing, and that has been an issue across the nation,” Ms Berejiklian said.

“If you ask the border communities, they will tell you I’m being too tough, not being relaxed enough, I don’t think so. I think our response is adequate, but if we need to do more, we will. We will know in the next few days what that flow is like as a consequence of the shutdown in Melbourne.”

NSW Health authorities have also confirmed four infections in a single family from Wagga Wagga.

They are a 52-year-old woman, her son and daughter-in-law in their 20s and the couple’s baby. All are self-isolating at home, and their infections will be included in Tuesday’s NSW update.

Ms Berejiklian continues to strongly recommend NSW residents wear masks in high-risk situations as the state enters a critical phase in the coronavirus battle.

Public-facing workers, worshippers, people living near community clusters and those in enclosed spaces, such as on public transport or in grocery stores, should wear face masks.

“These are recommendations to keep all of us safe,” she said.

“They’re recommendations to make sure we keep NSW in the position we are in. I cannot stress enough how critical the next few weeks are.”

NSW health authorities on Sunday confirmed a case connected to Sydney’s Potts Point cluster worked at Toronto Drug Court last Monday.

The court underwent deep cleaning on Sunday and everyone who was at the court that day should monitor themselves for symptoms.

Another man who had visited Sydney and picked up COVID-19 visited Newcastle venues Hotel Jesmond last Wednesday and Wallsend Diggers and the Lambton Park Hotel on Thursday, with all three venues to undergo deep cleaning.

Patrons at certain times on those dates must now self-isolate for 14 days and get tested.

“This action is vital to limit the spread of the virus,” Hunter New England Health’s Dr David Durrheim said in a statement on Monday.

Wallsend Diggers chief executive John Hume said he was contacted by NSW Health on Sunday and due to coronavirus regulations every visitor on that evening had been identified. The club is expected to reopen on Monday.

Ms Berejiklian stopped short of making masks compulsory but said elderly people or those suffering underlying health issues should also wear masks.

“We have been talking about masks for several weeks but obviously the persistent situation in Victoria gives us cause for alarm,” she said.

An 83-year-old man connected to the Crossroads Hotel cluster in southwestern Sydney died at the weekend, taking the NSW death toll to 52 and the nationwide tally past 200.

It was the first coronavirus-related death in NSW since late May.

On Sunday, NSW Health confirmed a person with coronavirus attended the Advanced Early Learning centre in Merrylands, in western Sydney, between July 27-29. The childcare centre has closed for cleaning.

The Thai Rock Wetherill Park cluster is nearing 100 cases, while the cluster in east suburban Potts Point has reached 24

-with AAP