The NSW Rural Fire Service (RFS) says two houses have been destroyed and people are trapped in their homes, as an unprecedented bushfire emergency grips the state.

The homes were wiped out around the Coraki area on the far-north coast and left a resident and a firefighter in hospital suffering smoke inhalation.

There are multiple reports people are also trapped in their homes in several locations because fire crews cannot reach them due to the intensity of the blazes.

The RFS said firefighters were in "uncharted territory" and at the peak of the crisis, a record 17 blazes burned simultaneously at emergency level.

More than 50 other blazes across NSW remain out of control.

RFS commissioner Shane Fitzsimmons said parts of the M1 motorway and the New England Highway were closed and he warned other road closures could leave people trapped.

"You've got to understand a lot of the access roads in and around many of these fires are more dangerous than staying in a shelter or a safer place in your local community or your property," he said.

"The principle message is about sheltering and sheltering in place — it's simply too dangerous and too late to leave."

A house can be seen on fire at Bobin. ( ABC News )

An RFS spokesperson said due to the size and speed of the fires, crews could not reach many people who called for help.

Those affected were encouraged to use the Red Cross emergency registration service.

Mr Fitzsimmons said almost 1,200 firefighters and 70 aircraft had been deployed "to save as many people as possible".

"We cannot emphasise enough the volatility and danger associated with all these fires," he said.

Towering flames near the Kularoo Nursing Home in Forster. ( Facebook: Jacki Pocock )

Mr Fitzsimmons also said the energy produced by each fire was influencing the behaviour of those nearby due to their close proximity, and most were spreading at twice the normal pace.

The worst of the state's fires stretch from Forster on the state's mid-north coast right up to Coraki, south-west of Ballina.

Emergency warnings had been issued for fires at Wandsworth, Torrington, Tyringham, Willi Willi, the Tapin Tops National Park, the Crowdy Bay National Park, Hillville, Kangawalla, Muck Creek, Coombes Gap, Bora Ridge, Stockyard Flat, Carrai Creek, South Arm and McHughs Creek, the Chaelundi State Forest, the Marara State Forest and Willawarrin.

A blaze in the Woodford area of the Blue Mountains had earlier been at emergency level but dropped back to watch and act.

The fires around Port Macquarie have given the entire region an eerie orange tinge, with one resident describing the scene as "apocalyptic".

It's nothing but red across Lighthouse Beach. ( Supplied: Laura Begbie )

Hillville resident Derek Eastham's home was spared but the fire completely wiped out his vintage collection of cars.

This was the fourth fire that has closed in on his property in the last week.

"It's devastating … [the cars] were really special to me … I've lost quite a lot of money in them," he said.

Derek Eastham lost a vintage boat he had hoped to give to his grandchildren. ( ABC News )

Mid-Coast Council Mayor David West said 92,000 people in the major centres of Forster, Crowdy Bay and Harrington were affected.

"I'm looking out of my office window and all I see is what I'm assuming people in London saw during the Second World War — it's a horrible, horrible sight," he said.

"It doesn't seem that we as human beings have anything we can throw at this beast that can control them."

He praised the firefighters battling the blaze, including many being deployed from other parts of the state.

"These guys and ladies are doing this without any fear. They're laying their lives on the line for us — it's unbelievable," Mr West said.

"We don't have any vegetation but it is incredibly dry, there is no moisture in the air, the wind is ridiculous and we are just being hammered and I guess everyone is fearful from the fallout from the ash," he said.

Residents preparing to leave their properties in Hillville. ( ABC News: Jonathan Hair )

Jodie Sutor said flames from a fire at Wardell, south of Ballina, reached right up to her back fence before spotting onto her neighbour's roof.

"As soon as you put one out, another fire would start up," she said.

"She started screaming 'It's on the roof', so we ran out and that's when I noticed small spots out the front.

"All out the backyard is burnt. Trees out the back are all up in flames. It's just so quick."

A fire crew stopped to rescue two dogs running around at Rainbow Flat near Taree on Friday afternoon. ( Facebook: Station Officer Peter Ward )

RFS Commissioner Mr Fitzsimmons said drought conditions meant there was a high fuel load and strong winds were causing embers to spot up to 12 kilometres ahead of the fire fronts.

Since August the RFS has battled hundreds of fires across the state.

In October two people lost their lives as bushfire ripped through the Long Gully area in northern NSW.