Fire and emergency are battling a large scrub fire on the Tiwai Peninsula in Southland.

Pictures circulating on social media show a large plume of smoke, visible from the nearby town of Bluff.

Acting Fire and Emergency shift manager John Ditmer said the fire is not yet contained.

"Due to information received from the scene, four helicopters were responded with an additional nine appliances and support vehicles being responded shortly after."

Ditmar said no buildings, including the nearby Tiwai Point smelter, are currently threatened.