The move followed a crisis meeting of government and health officials after a worker at a pet food factory at Blayney, near Orange, tested positive.

At yesterday's media conference, NSW chief health officer Dr Kerry Chant gave a sense of how seriously the news was being taken .

"We are currently urgently assessing the situation," she said.

Just hours later, the NSW government announced the first lockdown in regional NSW for this outbreak.

The Blayney factory worker caught the virus from a truck driver who delivered goods from Sydney on Friday and Saturday last week.

The Nestle Purina factory in Blayney is now closed for cleaning and managers are nervously awaiting the results of testing from a number of other workers.

Making matters worse, it has emerged that the Sydney truck driver made a number of stop-offs in Orange, visiting a petrol station, a Woolworths supermarket, a Pizza Hut restaurant, an Officeworks store and a shopping centre.

All five have been listed as venues of concern.

Anyone who was there at the relevant times is considered a close contact and asked to get tested and isolate for 14 days regardless of the result.

Deputy Premier John Barilaro said the lesson to be learned from how quickly the Delta strain was spreading in Sydney was to lockdown immediately, hard and fast.

"This is tough but it's appropriate, and if we go hard, fast, and local as we've done this time, we'll be out of this lockdown quite quickly," Mr Barilaro said.

"It's better we're safe than sorry but I'm confident that the seven-day turnaround might be sufficient."

Testing centres in the Central West are being expanded to cope with an expected surge in demand and hospitals have been placed on red alert, limiting access to visitors.

"We are all concerned because we just do not want this to escalate in our region at all," the Mayor of Blayney Shire Council, Scott Ferguson, told the ABC.

There are also concerns about the Illawarra region south of Sydney after a third person tested positive.

The latest case in Wollongong is linked to two others announced on Sunday.

"Case investigations are underway," a spokesperson for the Illawarra Shoalhaven Local Health District said.

"However, it is believed there are links to employment in the Sydney area."

The Central West was already on high alert after a visit from three removalists from Sydney, one of whom had tested positive for COVID-19.

Despite public health orders banning non-essential travel outside Greater Sydney, police allege the men set out for the 600-kilometre round trip from the Liverpool area of Western Sydney on Friday.

Their first stop was Figtree in the Illawarra before they continued on, driving across the Blue Mountains and making another call at South Bowenfels on the outskirts of Lithgow.

From there, they headed on to Molong, 150 kilometres further west.

It's believed to be while they were en route that one of the men received a call from NSW Health telling him he'd tested positive for coronavirus.

Officers alleged that the trio decided to continue their journey regardless.

Removalists have also been identified as the source of a COVID-19 exposure in the Hunter.

Two service stations have been identified as possible exposure sites.

Coffs Harbour:

Alarm bells have also gone off in Coffs Harbour on the Mid North coast of NSW after a positive case from Sydney visited a bottle shop on Thursday.

Police are investigating whether there was any breach of public health orders.

In a sign of the growing alarm about the spread of virus outside of Greater Sydney, new public health orders have been issued, stating that employers in regional areas must now allow people to work from home where possible.