Rural fire crews will be keeping an eye on a large bush fire along Tiwai Road tonight until further services can return with better visibility tomorrow morning.

Fire and Emergency New Zealand shift manager Andrew Norris said fire services were called to the vegetation fire at 6pm this evening. The burn measured a couple of square kilometres in size and was located on the Bluff side of Tiwai Road, on the northern side of Awarua Bay.

There were no affected properties in the area "other than probably a few maimais from the duck shooters," he said.

Two fire engines and two tankers from Invercargill attended the fire, but since access to the burn was difficult and it was nighttime, services would return to the site tomorrow morning.

For the meantime, specialist crews from Drummond and Hedgehope would be monitoring the burn overnight, he said.

UPDATE (5 May 2019 - 10:38am)

Shift manager Lyn Crosson said at least one Department of Conservation fire crew returned to the site at 9am this morning. There were no remaining flames and only a few hot spots.

A helicopter had been expected to fly over the site at 10am.