Pattani, Thailand - Thai forces on Tuesday killed six suspected Muslim separatists in the southern province of Pattani after failing to persuade the militants to surrender, police said.

Police and soldiers opened fire on a band of armed separatists after surrounding them in village huts near Kopoh town, 700 kilometres south of Bangkok.

"We had been tipped off that the rebels were going to enter the area as part of a big offensive," Pattani police chief Major General Phichet Tittisetthaphan said.

Police spent five hours trying to persuade the band to surrender but finally opened fire on them at 4:40 pm (0940 GMT) when the negotiations failed, he said.

"If we had waited until it got dark, the situation would have been very dangerous," Phichet told the German Press Agency dpa.

Two policemen were injured in the clash. Police found six suspected rebels dead in the huts, and various weapons including AK47 assault rifles, grenades and pistols.

It was the latest bloody clash in Thailand's three southernmost provinces - Narathiwat, Pattani and Yala - which have been plagued by violence since January 2004, when Muslim militants raided an army depot, killing four soldiers and making off with weapons, escalating a long-simmering separatist struggle in the region.

An estimated 3,500 people have died in clashes, bombings, revenge killings and beheadings in Thailand's deep South.

About 80 per cent of the region's 2 million people are Muslims. Of the 300,000 Thai Buddhists who lived in the region, some 70,000 have reportedly left their homes over the past six years.

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)