Fire crews have continued to face challenging conditions this weekend as they continue to contain and suppress the 1350 hectare fire in a significant wetland at Awarua Bay, south of Invercargill.

Incident Controller Julian Tohiariki said that the fire is contained within the 24km perimeter, but flare-ups are still occurring due to the large amount of flammable vegetation still remaining in the area.

A 50 metre wide control line has been established around 90 percent of the perimeter.

Five crews have been working today to extend that buffer in the remaining area to minimise the risk of any flare up breaking out of the perimeter.

They have also been using hand tools and portable pumps to expose and extinguish hotspots identified by thermal imaging, with support from two helicopters.

A helicopter and one crew were transferred to work on a nearby fire on Tiwai Road this morning, to ensure it was fully extinguished, and then returned to the main fire.

The second fire began as a car fire under a transmission line power pylon and spread to dense manuka scrub. It was only contained thanks to quick work from Invercargill and Tiwai Point firefighters. Inspector are now investigated this fire.

Weather permitting, drones will make another aerial assessment of the Awarua fireground tomorrow morning, Tohiariki said.

Tohiariki also reiterated calls for people to stay well away from the fire ground, where hazards range from deep ash pits to smouldering peat beds.

"People may be thinking that it’s safe to go there if they don’t see flames and plumes of smoke, but this is still an active fire and our crews need to be able to concentrate on their task rather than worrying about people trying to access their maimais."

Fish and Game Southland manager Zane Moss advised the Southland App on Friday (8 April) that duck hunters do not need to tag their maimai or pond within the active fire area this year, and that their pegs from last season will suffice for this year.

There is no public access to Awarua Bay Road past the intersection with Buddle Road, and there are signs at the boat ramps on the Waituna Lagoon advising that the wetland is closed to the public.