Reclaim Australia supporters welcome mosque blaze

A second suspected arson attack on a southeast Queensland mosque has been labelled as a "shocking" and "outrageous" crime against religious tolerance.

Speaking from Toowoomba, Police Minister Jo-Ann Miller said the violent attack had appalled the Palaszczuk government and would not be tolerated.

Police are investigating the second suspicious blaze at the Toowoomba mosque in the space of three months.

"We are totally disgusted by it," she said.

"We've come a long way in Australia ... we will not tolerate this anymore."

"It is shocking, it is outrageous."

The community must rally to outlaw those who disrupt others wanting to practise their religion peacefully, she said.

Islamic Society of Toowoomba founding president Professor Shahjahan Khan said the mosque hadn't received any explicit threats before the attacks.

"We have nothing against you - we haven't done anything wrong against you," he appealed to perpetrators.

"We are happy to forgive them if they come forward."

The congregation acknowledged their actions didn't reflect the broader community, he said.

Mayor Paul Antonio seconded the sentiment and said the city was determined to uphold its reputation for "peace and harmony".

But the suspicious fire has also inflamed tensions with anti-Islam groups, such as Reclaim Australia.

The group hit the headlines earlier this month after holding nationwide - and at times, violent - rallies to oppose "sharia law, halal tax and Islamisation".

Its Brisbane Facebook page was swamped with comments praising the apparent mosque attack after administrators posted a news article about the blaze.

"Just another 'False Flag' to make themselves look like the victims of hate crimes," one man wrote.

Another went so far as to congratulate those responsible: "Who ever (sic) lit it up is a champion."

"Damn I'm all out of marshmallows," another said.

Police have doorknocked the area and collected CCTV footage to try to track down those responsible.

The mosque site has also been declared a crime scene as scientific officers pore over the damage.