Thailand's prime minister, Thaksin Shinawatra, has upset neighbouring Malaysia with claims at the weekend that separatist Muslim militants fighting for an independent state in southern Thailand were being trained in jungle camps in Malaysia.
The accusation, made in Mr Thaksin's weekly national radio address, was angrily denied by Abdullah Ahmad Badawi, the Malaysian premier, who said he was "shocked" that Thailand would make such serious charges about a friendly neighbour in public, rather than though diplomatic channels.
"Of course we don't know that this is happening," Mr Abdullah told Bernama, Malaysia's national news agency. "Malaysia is not a base that can be used by any group who are planning to take action against another country. That is our clear stand."
In his comments, Mr Thaksin said he did not blame the Malaysian government, which he said was unaware of the activities. But that hardly mollified Kuala Lumpur.
"We question Thaksin's motive for making the statement," Mr Abdullah said. "If [he] has such information, he should convey this to Malaysia through diplomatic channels."
The rise in tensions comes as a just-completed report has apparently found three top-ranking security officials, including Mr Thaksin's brother-in-law, responsible for the deaths of 85 Muslim protesters who suffocated in the back of army trucks after their arrests in October.
The killing of the unarmed detainees at Tak Bai was the worst military atrocity in Thailand in more than a decade, and provoked an outcry across the Muslim world. In a report submitted to the premier on Friday, but not yet made public, an investigative panel said it had no evidence the deaths were "intentional" but identified three top government officers responsible for crowd control and concluded that the decision to pile detainees on top of each other was "at least negligent".
Since Thailand's three volatile southernmost provinces were put under martial law in January, more than 560 people have been killed in sporadic attacks by alleged insurgents and reprisals by Thai security forces.
On Friday, Thai authorities charged four Muslim teachers with treason and terrorism for allegedly plotting to establish an independent state in the region, which is now home to Thailand's deeply alienated ethnic Malay Muslim minority.
Parent site: "Focus on Malaysia"