Four Buddhist villagers are killed and their homes are set on fire in southern Thailand. Buddhists are often the target of rebels believed to be separatists.

Four Buddhist villagers were shot dead and their homes set ablaze in Thailand's troubled Muslim south on Sunday.

The incident is the latest in a spree of deadly attacks blamed on separatist rebels. More than four thousand people have been killed and eight thousand wounded in six years of unrest.

The incidents all took place on Saturday night.

Police suspect the attacks were carried out by a group of about ten ethnic Malay militants riding in a pickup truck armed with M-16 assault rifles.

Among the victims was an 83-year-old man shot dead before his house was burned to the ground.

The rebels then stormed another house nearby, shooting dead a 46-year-old man and his wife before torching the building.

A 76-year-old woman was later killed in the same district in another gun and arson attack.

The incidents came amid a recent upsurge in violence in the once independent Muslim region, where Buddhists represent about 15 percent of the population.

No credible group has claimed responsibility for the violence or stated goals or demands.

A combined police and military security force of around 60 thousand has failed to make any inroads towards quelling the unrest in the region.