A scattering of bins from Alford Forest Rd to Tancred St, put out last night for collection today, were randomly targeted and their contents set alight.
The bins have left a mottled mess of melted plastic and burnt remains behind.
Police confirmed they had received a report about wheelie bins on fire on Alford Forest Rd about 2.45am on Wednesday.
The fires were attended to by the Ashburton Volunteer Fire Brigade.
More bins were found alight on Short St, Tancred St and outside Cleavers Corner restaurant on the corner of Tancred and West Sts.
"A short time later another fire was located on the grass verge, Tinwald side of the Ashburton bridge," police said.
"All of these are reported to have occurred over a 40-minute time frame."
Police are following lines of enquiry but anyone with information that could help should phone 105 - or Crime Stoppers anonymously 0800 555 11 - and quote file or event numbers P049656611 / 220216/5099.
