NARATHIWAT - SEPARATIST insurgents shot dead six people including a village chieftain in Thailand's violent Muslim-majority south, police and relatives said on Tuesday.

Three village defence volunteers were gunned down by militants as they entered a marketplace on their motorbikes in troubled Narathiwat province on Tuesday, police said.

The victims were two men, aged 51 and 43, and a 42-year-old woman. A fourth villager was injured by a stray bullet and taken to hospital.

On Monday night, a 50-year-old village head was killed at his Narathiwat home after eight armed militants broke in and opened fire, his wife said.

A 39-year-old former security guard was shot dead on the street and his four-year-old son shot in the leg earlier that evening in the same province, police said.

The child remains hospitalised in a serious condition.

In Yala province, a 46-year-old former policeman was killed on Monday in a drive-by shooting.

More than 3,500 people have been killed since separatist unrest erupted almost five years ago in Thailand's Muslim-majority south.

Tensions have simmered since Thailand annexed the mainly Malay sultanate in 1902. -- AFP