Emergency services are racing to a truck fire on State Highway 7 near Hanmer Springs.
Fire and Emergency New Zealand says they were called to the scene shortly before 9am after reports of explosions from fellow truck drivers on the scene.
Authorities estimate there could be 10 to 12 different chemicals on the truck but couldn't identify what those chemicals were.
Police are evacuating the nearby Boyle Village north of the incident for safety reasons due to the amount of smoke and potential hazards from the fire.
The Lewis Pass is currently closed between Hanmer Springs and Springs Junction.