Twenty firefighters from New Brunswick will be arriving Wednesday to help battle a persistent forest fire near Kejimkujik National Park in western Nova Scotia.

The provincial Department of Natural Resources said weather conditions Tuesday night provided more favourable conditions for crews actively battling three fires in the province:

Seven Mile Lake in Annapolis County — 240 hectares, out of control.

Ten Mile Lake in Queens County — eight hectares, containment expected Tuesday.

Clyde River, Shelburne County — 2.5 hectares, containment expected Tuesday.

Perch Lake, Pictou County — contained.

West Dalhousie, Annapolis County — contained and under control.

Maitland Bridge, Annapolis County — contained.

Greenfield, Queens County — contained and under control.

Collingwood, Cumberland County — contained.

Air quality alerts

Environment Canada issued special weather statements for Annapolis, Kings, Lunenburg and Queens counties on Tuesday, warning of smoke and reduced air quality due to the Seven Mile Lake fire.

"Higher pollution levels are expected to persist through Wednesday," the agency said.

The provincial Department of Natural Resources pulled out crews fighting the Seven Mile Lake fire in Annapolis County on Monday evening. (Communications Nova Scotia)

The fire burned through 100 additional hectares of forest overnight and now covers 240 hectares in Annapolis County, Department of Natural Resources officials said Tuesday.

"We really need some weather to co-operate with us and we're not getting that right now," said Jim Rudderham, the department's forest protection operations manager.

'Came to life again' overnight

Ground crews were forced to pull out of the area on Monday evening when the fire "came to life again."

They came back on Tuesday, with water bombers dumping water and retardant on the perimeter of the fire while ground crews attacked it on the rear and sides.

DNR says depending on wind and other weather factors, the fire has the potential to spread at 25-30 metres a minute or a kilometer and a half per hour.

The fire at Seven Mile Lake has spread to 240 hectares, a 71 per cent increase since Monday. (Communications Nova Scotia)

Fast-moving fire

"It's going to be the ground crews that are going to extinguish that fire," said Dave Steeves, a firefighter and spokesman for the department.

"We need the winds to slow down and we need either a big increase in relative humidity or some type of precipitation event."

Extremely dry conditions and gusting winds are adding to the challenge as the fire moves through Crown land and is travelling east.

There has been no evacuations and no structural damage to any property.

Two helicopters and four water bombers are now working on the fire at Seven Mile Lake. Two aircraft from Quebec were expected to arrive Tuesday afternoon. (Communications Nova Scotia)

The fire moved so fast that Rudderham says crews haven't been possible to remove brush and create a fire break — an open space the fire won't be able to jump across.

Dozens of firefighters with the Department of Natural Resources, as well as 19 volunteer firefighters and four people from Parks Canada were working to contain the blaze Tuesday. Nine fire trucks, six pieces of heavy equipment, two helicopters and six water bombers — including two from Quebec — were also on the scene.

"All that we've had left we've thrown at that fire," Rudderham said from the province's wildfire co-ordination centre in Shubenacadie.

A firefighter battles the Maitland Bridge fire. The fire is considered contained. (Communications Nova Scotia)

'Scared to death when the phone rings'

Part of the problem is that the fire is burning deep into the forest's root system.

"The ground is just so dry, all the fuels in the ground are so dry. In places these fires will burn in the ground two feet or more. You physically have to dig them out and put the fire out," Rudderham said.

Grounds crews are still looking for hot spots and mopping up fires like this one Maitland Bridge and another in Greenfield, Queens County. (Communications Nova Scotia)

"That's why the woods are closed. Just try to reduce any starts. We're just scared to death when the phone rings here."

Thick smoke from the fire was interfering with visibility on Highway 8 near Maitland Bridge. Some resources from this area are expected to move to Seven Mile Lake on Wednesday as that fire is now contained.

Trails off limits

CBC meteorologist Kalin Mitchell said the dry conditions will continue as there is no rainfall expected Tuesday or Wednesday. There should be some isolated showers on Thursday and Friday and widespread rainfall isn't expected until Saturday.

The dry weather prompted the provincial government to restrict hiking, camping, fishing and using off-highway vehicles in wooded areas.

A tree stump sprayed with water to prevent a possible flare up. (Communications Nova Scotia)

People will still be able to access beaches and provincial parks close to wooded areas but they will not be able to hike on Crown land.

The restrictions began at noon on Tuesday. People who defy the ban could be fined $180.

Parks Canada also closed backcountry campsites and trails within Kejimkujik National Park as until further notice. Kejimkujik Seaside is also closed. Campers could be seen packing up and leaving the park on Tuesday afternoon.