The majority of bushfires raging across Queensland amid a statewide emergency have been deliberately lit, an expert believes.
Police have set up a special task force probing several blazes as the state reels from days of property damage and displacement which is set to continue into the weekend.
Eight fires - in Brisbane, Stanthorpe, the southeast and central Queensland regions - are in the scope of the taskforce as more than 80 fires rage across the state on Tuesday, police commissioner Katarina Carroll says.
It comes after three teenagers were questioned after allegedly admitting online they were responsible for a bushfire which has destroyed two homes and forced hundreds to flee on the Sunshine Coast.
"Some of the behaviour, unfortunately, has been reckless and other behaviour has been purposeful," Commissioner Katarina Carroll said.
"Some of the fires have involved children playing and obviously the consequences are dire as a result of that.
"Some of them have been purposeful and malicious. Some fires have clearly just gotten away from kids thinking they're having fun."
On Monday, three young boys were arrested for lighting a fire in a stormwater drain on the Gold Coast, while a 63-year-old man was charged with lighting an unauthorised fire after allegedly back-burning just outside Rockhampton on Sunday.
A 12-year-old boy was being questioned on Tuesday over a deliberately-lit fire which destroyed bushland and a section of a Logan City Council storage facility at Woodridge on Monday night.
Police are also appealing for information about three suspicious fires west of the Sunshine Coast on Saturday.
The behaviour has occurred despite 'very high' fire ratings amid windy and dry weather conditions.
"We have a number of people across the state who are not exercising prudent care with fire," Chief Superintendent Ben Marcus said.
"People are still throwing cigarette butts out the window, people are still operating grinders, people are still producing ignition sources."
At least 17 houses have been destroyed and 67 damaged.
Paul Read, a director of the National Centre for Research in Bushfire and Arson, believes around 50 per cent of all Australian bushfires are confirmed or suspected arson, with only 15 per cent occurring naturally.
He speculated up to 95 per cent of current bushfires in Queensland were caused by human activity such as arson, reckless use of machinery or land clearing.
"Usually, there's a portion that are lightning strikes. There have been no lightning strikes," Prof Read, from Monash University, told AAP.
Professor Read believes adult arsonists were "embittered" and depressed, often from loss of employment or the break-up of a relationship.
Children would deliberately lights fires because they have developmental disorders or were playing only for the fire to get out of control, with lack of education a factor, he said.
Other children were "truly malicious" and were "heading towards developing full blown psychopathy".
"That group needs to be handled by the justice system," Prof Read said.
Australian Associated Press