Emergency Services Minister Joe Francis said that arson was an act of "urban terrorism" as he applauded WA police on Thursday for making a 500 per cent increase in arrests during its annual crackdown on bushfire-starters.
Strike Force Vulcan ended its fourth campaign with 16 arrests and 37 juvenile cautions over a four-month period - compared with three arrests and 22 juvenile cautions last year.
Another success was there were no repeat offenders.
"Lighting a bushfire is one of the worst acts. It causes closure of roads, puts people and properties in danger and causes a lot of frustration for firefighters and the police. It is an act of bastardry," the minister said.
"There are signifcant penalties for arson - up to 20 years in jail."
Most of the offenders were boys, mainly aged between 10 and 17, with the youngest eight years old.
Police determined 533 fires were arson incidents, a figure little changed from 566 in 2014, but they claimed the increased arrests were an indicator of successful investigations.
"Generally, these boys worked in small groups, but the level of sophistication amounted to little more than a box of matches or a lighter and an opportunity," said the officer-in-charge of the Arson Squad, Detective Senior Sergeant Craig White.
He said offences were spread throughout the metropolitan area and most fires were contained, but ones like the recent Baldivis blazes showed how they could get out of control.
Detective Senior Sergeant White said police would work with Edith Cowan University in the coming months on a study aiming to understand the motivation for boys to start fires.
"We want to identify the urge, find the trigger that makes them suddenly decide to start a fire on the way to or from school, after walking that same [route] regularly (without incident).
There were six adult offenders.
