Police are looking for a pyromaniac at the seaside settlement of Piha, west of Auckland.
Officers are investigating a spate of suspicious fires on Monday and early this morning.
Police said a number of scrub fires were lit on tracks and on Lion Rock, around midnight.
They said the fires were a destructive and senseless act of vandalism, and officers were working with the fire service to find whoever was responsible.
There will be an increased police presence in the area.