KEY POINTS:

- The fire has taken control of 2100ha, with a 27km perimeter.

- 2500 to 3000 people have been evacuated.

- 170 homes were on standby to evacuate overnight.

- Two men have been arrested on arson-related charges

Fire crews have prepared all they can for the stronger winds forecast in Tasman this afternoon where a massive blaze has burned since Tuesday.

At a media stand up this morning, fire crews revealed that they have 100 per cent of the perimeter contained, but that is not entirely secure. 

Fire and Emergency New Zealand incident controller John Sutton said the fire was active last night but the weather conditions for control efforts were favourable with light winds.

"It's moving very, very slowly," he said at a press conference this morning.

"We now predict with the current fire it will take six hours for that fire to burn to the river flats from where it is."

Sutton said the fire was less than 10km away from Wakefield. He described the river flat area was a double-edged sword, if the fire moved there it was the best opportunity to put it out but if it had strong wind behind it they would not be able to put firefighters in front of the moving blaze.

"It's not contained."

"I am worried about tomorrow, to be honest," he said.

Reporter Chelsea Daniels told Francesca Rudkin that they are working to create a "buffer zone" between the fire zone and the perimeter of around 30 metres.

However, if the wind picks up, that could put the effort at risk. 

"Winds are expected to reach 45 kilometres this afternoon. They are pretty confident they can manage 50 kilometres an hour. Once it gets past there, they will have to start bringing down the helicopters and bringing out the men." 

Inspector Zane Hooper, Acting Tasman District Commander said SH6 remained closed with limited access.

"We are constantly reviewing the closure of state highway 6."

Overnight there were a large number of patrols bolstered by the NZ defence force in affected areas, he said.

Kevin Kim, from the NZ Defence force, said people needed to use the traffic diversion in place.

"We are currently prioritising safety of the community."

The Nelson fire seen after a flare-up near Wakefield on Thursday. Photo / Aimee Jules

Nelson Tasman Civil Defence incident controller Roger Ball said there was still no end to the state of emergency in sight.

More than 1000 properties had been evacuated affecting about 2500 people, he said.

Tasman Mayor Richard Kempthorne said for people that are away, it can be hard to imagine how dry the conditions are and how dangerous it is.

"The fire can change very quickly," he said. "We are still in a volatile situation."

Civil Defence earlier announced it had put a ban on certain activities in part of the Nelson Tasman region in order to reduce the fire risk as a large blaze continues to rage.

Controller Rob Smith announced this morning that those using certain types of outdoor machinery would need to hold off because "one spark could be enough to cause a fire in these conditions".

Farmers, contractors and anyone using such machinery in Nelson and the Waimea and Motueka valleys will need to defer their activities because of the extreme fire danger.

The directive was issued under the Civil Defence Emergency Management Act and the following high-risk activities are prohibited in the defined area for the duration of the State of Emergency.

• Prohibited activities include those where metal meets stone: mowing, discing, harrowing, stump grinding and cultivation.
• Outdoor activities that can generate sparks or fire are also prohibited, and include gas cutting, welding, angle grinding, and all use of chainsaws and scrub/bar cutters.
• Commercial forest harvesting activities are also to cease, but provision can be made for the loading and mobilising of harvested material from landings.

Smith said he was mindful this would cause some inconvenience, but it was an essential precaution to help prevent more fires during the current period of extreme fire danger.

"We are not expecting this directive to limit activities where there is adequate [pressurised] fire control available, or those activities not generating fire risk such as horticultural spraying or feeding stock," he said.

"Landowners should be aware that many activities on land can cause fires and people should take action and be aware of what constitutes good fire management protocol.

"For example, not parking vehicles on long, dry grass, disposing of cigarette butts inside your car, mowing domestic lawns, and making sure electric fences are not arcing.

The prohibition will be reviewed on Tuesday, when the present Civil Defence-declared emergency is reviewed.

Kempthorne told Francesca Rudkin that any businesses affected by these bans will be able to contact the Ministry of Social Development to get money for wages.

He says the ban is more aimed at rural properties, but that people in the cities should pay attention as well.

"If you can put off mowing your lawn until it rains, that would be a good thing to do."

Rural firefighter Dave Houston manning a pump on the fringes of the Tasman bush fires at Teapot Valley near Nelson. Photo / Mark Mitchell

The announcement comes after an estimated 170 houses were asked to prepare to evacuate in the Wai-iti area, just south of Wakefield, last night.

They join a mass movement that has already displaced about 2500 to 3000 people - as the fire has taken control of 2100ha, with a 27km perimeter.

Daniels says that there has been some frustration from residents on how they were being briefed, which Civil Defence has taken on board.

She spoke with one man who described his evacuation as feeling more like an arrest. 

Kempthrone says that he and Civil Defence are aware of how challenging the evacuation is for people, but the primary goal is to keep people and property safe.

As of 11.30pm yesterday there were still active hotspots continue to hamper efforts for re-entry in Eves Valley, and an active fire area in Pigeon Valley. Teapot Valley was said to be a matter of priority for this morning.

"The priority for this operation remains protection of life and public safety," Civil Defence said.

Anyone preparing to evacuate was asked to find any house pets and bring them inside, leave cellphones on and charged, prepare essential items such as food, clothing and medication, and ensure their vehicle had enough fuel for the return trip.

Meanwhile, two men have been arrested on separate arson charges unrelated to the fire. 

Both men, aged 27 and 24, have been charged over rubbish skip fires that are unrelated to each other.