Christchurch could be dubbed New Zealand's "Arson City" with firefighters scrambling to tackle a suspicious building blaze every three days since the start of last year.
Figures released by the city's Fire Service investigation unit show the number of suspicious building fires they attended in Christchurch rose by 50 per cent from 2011 to 2012.
National records show the Canterbury, West Coast, Tasman and Marlborough fire regionis home to more major blazes than any other in the country.
Senior fire risk management officer Mark Thomas said Christchurch could now almost be called "Arson City".
Among the more recent casualties are the historic Billens Building on High St, the old Konica Minolta building on Moorhouse Ave, half an Akaroa bakery, and a string of vacant red-zoned homes - the latest of which was on River Rd last weekend.
Thomas said that while minor arson attacks targeting wheelie bins, skips, grass, scrub and cabbage trees had decreased since the September 2010 quake, deliberate structure fires had increased markedly.
Investigators from his unit attended 115 suspicious building fires in 2012, up from 76 in 2011, and 89 in 2010.
Since January 1 this year, they had attended 145 deliberate fires in Christchurch, 18 of which were in homes or buildings.
Thomas said the increase was mostly driven by fires in abandoned quake-damaged or red-zoned houses, which appeared to be a target for people who lit fires for "excitement".
This not only posed a danger to firefighters but many of the houses showed evidence of occupation.
"We are now constantly apprehensive at each incident that a body or bodies may be discovered," he said.
"Do the people of this town want it to be known as Arson City?
"We're well on our way there now."
While much national data regarding deliberate fires was not recorded during periods of industrial action, anecdotal evidence suggested Christchurch was worse for deliberate structure fires than other main centres.
National Fire Service research and investigation unit records show region 4 (Canterbury, West Coast, Tasman and Marlborough) accounted for 34 per cent of New Zealand's "significant" fires since September 2011.
Of the 162 reports filed from the region, 120 were from Christchurch.
Region 1 (Auckland and Northland) accounted for 32 per cent for the same period, followed by region 3 (Lower North Island) with 17 per cent, region 2 (Mid-North Island) with 11 per cent, and region five (Otago and Southland) with six per cent.
Canterbury fire investigation co-ordinator Detective Sergeant Craig Farrant said police were aware of the increase.
The public, particularly in the residential red zone, was "right to be concerned", Farrant said.
Unlike other serious crimes where offenders had been found to fit a particular profile, an arsonist "could be anyone", he said.
Arsonists had seven possible motives: pyromania (a motiveless obsession with fire starting); profit or financial gain; crime concealment; hate/spite/revenge/jealousy; juvenile vandalism; excitement and fraud (for example insurance payout).
Farrant said deliberate fires would cost Canterbury millions of dollars each year in property damage.
A Canterbury Earthquake Recovery Authority spokesman said 24-hour patrols of the residential red zone were ongoing in a bid to prevent deliberate fires.
The number of fires in the red zone was trending down, he said.
Another Christchurch property was hit by arsonists last night.
A Fire Service spokesman said they were called to a house at 89 Carlton Mill Rd about 7.05pm.
Two appliances responded and the blaze was under control about 7.25pm.
Fire station officer Craig Jackson said the house appeared to be abandoned, with firefighters having to break through a piece of plywood screwed to the front door to get inside.
Jackson said the fire had been started upstairs but was contained to one room.
Someone appeared to have forced their way into the house to set the fire, he said.
Witness Ali Jones said her husband heard glass breaking and then saw two people biking away.
She said a neighbour followed the pair to the park and called police.
A police spokesman said last night two people had been taken to the police station for questioning.
Jones said the property, one in a block of flats, had been unoccupied for some time.
RECENT ARSON CASES
Recent arson cases: Feb 15, 2013 - 89 Carlton Mill Rd.
Feb 11, 2013 - 281 River Rd.
Jan 10, 2013 - Akaroa Bakery.
Dec 7, 2012 - Billens Building, Konica Minolta Building, Moorhouse Ave.
Oct 20/21, 2012 - Jollie Rd, Kaiapoi, Banks Ave, Dallington and Bromley.
Aug 25, 2012 - Alloway St.
June 24, 2012 - Riccarton Rd shops plus St Theresa's School on the corner of Puriri St and Riccarton Rd.
Feb 25, 2012 - Canterbury Rowing Club building, Kerrs Reach.
Feb 22/23, 2012 Sameera Chadrasena dies after an arson at his rented home near Oxford.
- © Fairfax NZ News