Two separate rural fires in the Waitaki District are now contained, after firefighters were alerted to them shortly after midnight last night.

The first fire is in the Nenthorn Area, about 30km east of Middlemarch, and the second in the Earthquakes area, about 7km from Duntroon.

Work to consolidate the perimeters and extinguish hotspots is now underway, Fire and Emergency New Zealand (Fenz) incident controller Bobby Lamont said.

At Nenthorn a small number of farm buildings have been destroyed or damaged, and 78 hectares of farmland burnt, an aerial reconnaissance this morning revealed.  

Three households self-evacuated last night, and residents were not yet able to return, as crews were still working near their homes. 

Nenthorne, Ramrock and Butter and Egg roads had all been closed.

The Middlemarch crew, which was first on the scene at Nenthorn, did "an amazing job" to protect a house from the flames. Crews from six other volunteer brigades also responded, as well as the command unit from Dunedin, Bobby said

Three tankers and five additional crews of firefighters, supported by three helicopters, continue to work Nenthorn this morning.

A fire investigator will be examining the area where the fire started to establish the cause, and two other fires were started by embers blown by the wind from the original blaze, Bobby said.

Incident Controller at that fire, Jason Sarich, said firefighters had worked very hard in challenging condition to contain the fire, with galeforce winds on the fireground overnight.

Meanwhile, the Earthquakes fire has burnt about 30 hectares of conservation land, and another 30 firefighters and two helicopters were working in the area this morning.

They would be joined by two crews of firefighters from the Department of Conservation later today. 

A Fenz command unit from Timaru is also at the scene.

Smoke from the Earthquakes fire was noticeable from Ōamaru and prompted several 111 calls earlier this morning. 

Advice from Fenz is if somebody sees or smells smoke and is concerned, to always call 111 so trained dispatchers in our communications centre can assess whether there is a new fire.

Fire and Emergency crew on the ground.