A wheelie-bin arsonist left mounds of melted plastic and a Dunedin suburb "saturated" with police patrols yesterday morning.
A Fire Communications spokesman said eight burning wheelie-bins kept crews from three Dunedin fire stations busy in the Mornington-City Rise area.
Senior Sergeant Kelvin Lloyd, of Dunedin, said police were keeping an "open mind" about the spate of arsons.
"We don't know if the offender was on foot or in a vehicle."
The arsonist had set the contents of the bins on fire and had not used an accelerant, Snr Sgt Lloyd said.