Health authorities in NSW have confirmed seven new cases of COVID-19 in the past 24 hours, four of which are travellers in hotel quarantine.

Two of the new infections are linked to a known case or cluster while one is still under investigation.

Testing rates fell to just over 8800 people, down from 9316 yesterday.

This is the lowest number of daily tests in more than two months for NSW.

NSW Premier Gladys Berejiklian had previously said the state should aim for 20,000 tests per day.

One of the new cases is a household contact of a case linked to Concord Hospital in Sydney’s inner west and another is a healthcare worker at Liverpool Hospital in Western Sydney.

One of the four travellers who tested positive was a NSW resident returning from Victoria.

All passengers who were on the same flight are also in hotel quarantine.

NSW Health also revealed a second student at Blue Mountains Grammar School has tested positive after an initial case on Saturday.

The new case will be included in tomorrow’s figures and the school is now closed.

Although community transmission is very low, NSW Health said the virus was still silently circulating in the community so the risk of outbreaks remains.

South-western, Western and south-eastern Sydney are at particular risk, NSW Health’s Christine Selvey said yesterday.

In the past four weeks, the south-western local health district has seen the lowest number of tests per 1000 people of all areas across Sydney.