Malaysia said Thailand should not try to stop its Asean partners from discussing the Muslim unrest gripping its southern provinces as the region needed to be informed of potential security threats.

Prime Minister Thaksin Shinawatra said Thursday he would walk out of the Association of Southeast Asian Nations (Asean) summit in Laos next week if leaders raised the deaths of 87 Muslim protester in the insurgency-hit south.

Asean's policy of not interfering in the affairs of its 10 members "should not let it happen", he said.

But Malaysia's Foreign Minister, Syed Hamid Albar, said there was "no such thing as absolute non-interference".

And while Asean members have no intention of interfering in Thailand's domestic affairs, they have a right to inquire about the situation because the threat could spillover to other countries, he said here.

"We don't want any of the Asean countries to become a breeding ground for a new form of terrorism," Syed Hamid told reporters.

"We know the Thais are able to handle it in a way that will bring peace and security in that province. But if anybody should ask that question, it should not be simply put aside as interference.

"The multilateral process is not for interference but for us to be well-guarded and to work together."

Not on agenda

The issue is not on the leaders' agenda at the summit starting Monday, but Malaysian Prime Minister Abdullah Ahmad Badawi was likely to raise the subject, the minister said.

"We are interested in the latest and current position because we don't want it to affect our country," he said.

Other Southeast Asian officials said Thaksin's hardline approach to the unrest, which has also raised concerns in Muslim-majority Indonesia, came as a surprise and could divide the 10-member grouping.

"We are shocked that they have chosen to clam up," said a foreign ministry official in the Laotian capital to prepare for the summit.

"In the past, Thailand has been inquisitive about developments in Myanmar. We thought that they would be more open about it when it comes to their turn," said the official, who asked to not to be identified.

"It is already dividing Asean," he said.

Another official said: "It has the potential to be divisive if not handled well. We don't want to see anybody walk out of the room."

Golden rule

Yong Chanthalangsy, the Laotian spokesman of the summit, said there was nothing unusual about Thailand's position because of Asean's strict policy of not interfering in the internal affairs of its members.

"I think we have a golden rule, that is non-interference in the internal affairs of each other," he told a briefing.

"It is a courtesy among the leaders, among the ministers, that if one of the leaders does not wish to discuss a question, all the leaders will respect it," he said.

Decades-old separatist violence in Muslim-majority southern Thailand resurfaced at the beginning of this year and has since left around 550 people dead.

Concern about the unrest was inflamed by the October 25 deaths of 87 Muslims protesters, mostly through suffocation after they were piled into army trucks. The killings prompted a spate of retaliatory attacks on Buddhists.

Thaksin said on Thursday ahead of the Asean meeting: "If the topic is raised, I will fly back home."