Pattani, Thailand - The military on Wednesday deployed hundreds of soldiers and police to capture a suspected key leader of the separatist insurgency in southern Thailand.

The operation to capture Masoleh Dellamah was launched on the outskirts of Pattani, 680 kilometres south of Bangkok, but after a clash, Masoleh and his followers managed to escape into a nearby jungle, authorities said.

Reinforcements and helicopters were called in to help track down the insurgents.

"Masoleh is one of the key leaders of the insurgency," Pattani Governor Theerathep Sriyaphan said. "He is skilled in bomb-making and has been responsible for many past terrorists attacks."

Masoleh was also the chief suspect in the murder Monday of a Thai policeman.

After five years of violence in the three-province region bordering Malaysia, there is no sign of an abatement in the conflict, which has killed an estimated 3,700 people over the past five years.

In the first two months of this year, there were 75 incidents of violence, leaving 38 people dead and 64 injured, authorities said.

Of the 300,000 Thai Buddhists who used to live in the region, about 70,000 have left since separatists raided an army depot in January 2004, killing four soldiers and making off with 300 weapons, leading to an escalation of the region's long-simmering separatist struggle.

The incident sparked a series of brutal government crackdowns on the separatist movement, which turned much of the area's 2 million people, 80 per cent of whom are Muslim, against the central government.

Although the region, which centuries ago was the independent Islamic sultanate of Pattani, was conquered by Bangkok about 200 years ago, it has never wholly submitted to Thai rule.

Analysts said the region's Muslim population, the majority of whom speak a Malay dialect and follow Malay customs, feels alienated from the predominantly Buddhist Thai state. (dpa)