Thailand's most-wanted Muslim separatist has been arrested in Malaysia and the kingdom will seek to extradite him here to face charges, Thai Prime Minister Thaksin Shinawatra said today.

Authorities have alleged Doramae Kuteh, also known as Chae Kumae Kuteh, was the mastermind behind a Jan 4, 2004 arms depot raid that reignited unrest in Thailand's Muslim-majority south that has left at least 570 people dead.

"Absolutely we want him extradited back here as he has been involved with many incidents. He has been the real mastermind (behind the unrest) including last year's robbery of government-owned weapons," Thaksin told reporters.

He did not elaborate on how and when the suspect was arrested but confirmed that he was captured alone and under Malaysia's Internal Security Act, which allows suspects to be detained without trial, for also posing a threat there.

"We are coordinating with Malaysia to determine his nationality but initially we will take part in investigations and we are now checking for evidence as well as on his Thai nationality," he said.

Doramae Kuteh is wanted for premeditated murder and inciting a guerrilla movement, and had a bounty of five million baht (about US$130,000) on his head.

One to surrender

Thaksin said another alleged separatist known as Sapae-ing had meanwhile made contact with authorities here.

"Sapae-ing has contacted authorities to turn himself in, but on condition of being granted bail. After the elections I will go to the south to personally oversee the crackdown," he said.

Both developments were likely to mean an improvement in the restive southern provinces bordering Malaysia ahead of Feb 6 elections.

Security forces have struggled to quell the Islamic insurgency that erupted in the area after the January raid.

The unrest has comprised almost daily attacks on police, troops, government officials and teachers at state schools. Buddhist monks and villagers have also been killed.

It also led to tensions with Malaysia after Thaksin claimed in December that Thai militants were training in the neighbouring country's jungles. Thaksin later backed off from the comments, claiming they had been distorted by the media.