No motive for Qld mosque fire: police

Police investigating a suspicious fire at a mosque in Queensland say they have no evidence the blaze was religiously or racially motivated.

An arson investigation is underway after a plastic bin was deliberately lit in a wooden building next to the main mosque building in Toowoomba just after 1pm on Saturday.

A gas stove had also been turned on, but the leaking gas failed to ignite.

The building sustained minor fire damage and Detective acting Inspector Paul Hart says there's as yet no indication of motive.

"At this point in time we haven't found any graffiti or any other communication that was left at the scene to suggest this was racially or religiously motivated," Det Insp Hart told the ABC.

"We're very well aware of the potential ramifications of community tensions around that aspect. At this time that part can't be confirmed so we're just treating it as we would for any normal offence."

The mosque - the Queensland city's first - opened last year after years of fundraising by local Muslim groups.

Det Insp Hart said a man in a hoodie could be seen on CCTV footage in the vicinity of the building at the time of the fire but there were no clear suspects at this stage.

He added while the fire appeared "ill-conceived", it could have been catastrophic if it had taken hold, particularly with the presence of gas.