Thailand's government has come under a barrage of criticism at home and abroad for the deaths of more than 80 Muslims while in police custody in the country's troubled south. A Muslim separatist group is now warning that there could be a violent backlash.
Bracing for possible reprisals, Thai Prime Minister Thaksin Shinawatra has called a meeting of his top advisors to discuss security.
The move comes as a long dormant Thai Muslim separatist group - the Pattani United Liberation Organization - issued a warning that there could be a violent reaction anywhere in the country to the government's deadly handling of a riot in the mostly Muslim south.
In Narathiwat Province Monday, police clashed with 2,000 Muslim protesters, killing at least six people. Authorities then detained some 1,300 people on the scene and jammed many into trucks for transport to a military facility hours away, crushing or suffocating 78 of the protesters.
Muslim Member of Parliament Surin Pitsuwan says the situation is grave.
"I think the situation is very, very critical and it could lead to a graver situation if no solution and no transparency is established," said Surin Pitsuwan. "I think the people down there are living in the atmosphere of fear and a lot of anger, a lot of frustration and despair."
Mr. Thaksin expressed regret for the deaths on Wednesday and promised an investigation. But he insisted the security forces took the right action to stop the demonstration.
Human-rights groups have repeatedly accused Mr. Thaksin of using excessive force to deal with the violence in the south, which has left more than 430 dead since January.
The government blames a renewed separatist insurgency that was largely quelled more than a decade ago after a government amnesty.
Muslim majority nations, Malaysia and Indonesia, have expressed outrage over the incident and the United States and human-rights organizations have called for a complete probe.
Muslim Member of Parliament Surin Pitsuwan says the deadly incident, which occurred halfway through the holy Muslim fasting month of Ramadan, has damaged Thailand's democratic reputation.
"I think the international community and the people in Thailand in particular, particularly the people in Thailand, are outraged and would like to know the truth, nothing but the truth," he said. "Otherwise, the situation will deteriorate."
Most of Thailand's 63 million people are Buddhist. But about 10 percent practice Islam, most living in the southern provinces bordering Muslim-majority Malaysia.