Extra planes sent to battle out-of-control NZ bushfire

Extra aircraft are being deployed to fight an out-of-control bushfire that has burnt through around 1100 hectares of national park in New Zealand's central North Island.

Firefighters began battling the fire in Tongariro National Park, a popular hiking spot, on Saturday afternoon and around 40 hikers had to be airlifted to safety. However, firefighting efforts were suspended overnight for safety reasons.

More firefighting planes were being sent to the area, taking the number of aerial assets involved to eight helicopters and three planes, Fire and Emergency New Zealand said on Sunday.

"Because of the terrain and extent of the fire, air attack is more effective at this stage than bringing in additional ground crews across most of the fireground," Fire and Emergency New Zealand assistant commander Craig Gold said in a statement.

Nine hikers were evacuated from the national park on Sunday morning, state-owned Radio New Zealand reported, citing a Department of Conservation spokesperson.

Fire and Emergency New Zealand said an aerial reconnaissance on Sunday would confirm the extent of the fire. Depending on what it showed, it was expected to take a full day of operations to bring the fire under control.

The agency said it would have six fire trucks and five tankers on the ground battling the blaze.