Politically motivated arson attacks have been blamed for 45 school fires nationwide in the last 100 days, including all 18 school torchings in the Muslim South, police spokesman Pol General Ajiravid Subranbasaj said yesterday.

There have been 84 fires in total across the country since September 1.

Of the 45 school fires, 14 of them were caused by electrical short circuits - the rest were arson attacks and politically motivated, he said.

All 18 school fires in the deep South were deliberate acts by Muslim insurgents.

He said the burning of schools in the north and northeastern provinces were clearly to copycat attacks in the South.

Gen Ajiravid condemned all arson attacks on schools as acts carried out by uncivilised people.

Former Thai Rak Thai MP Suphorn Atthawong, said TRT acting leader Chaturon Chaisang had never told any party member to torch schools.

The Nakhon Ratchasima-based politician complained that all TRT figures had been painted as villains whenever school fires took place in their constituencies.

He challenged "those in power" to bring the masterminds and arsonists to justice to show sincerity that they were not behind the school fires themselves.

He threatened to protest outside Government House if suspects behind the fire at a local school in his constituency earlier this week were not arrested within one month.

Army Commander and Council for National Security chairman Sonthi Boonyaratglin cited a military intelligence report as saying the arsonists who torched the schools were not locals in those areas.

Speaking to reporters in a brief interview yesterday, Sonthi asked them to help analyse who these arsonists could be and who hired them to commit the crimes.

He dismissed as nonsensical the earlier bomb threats at the Stock Exchange of Thailand and Suvarnabhumi Airport, saying: "Don't pay attention to them, or you will only have a headache."