YALA (Thailand) - SUSPECTED militants in Thailand's deep south killed nine people and injured two others in five separate attacks on the eve of a key anniversary for the restive region, police said on Tuesday.

Gunmen opened fire on a Muslim defence volunteer while he was watching a football match in Yala province on Monday evening, they said.

Another man was killed nearby in a drive-by shooting in the province's main Yala town minutes later.

Police said at least six gunmen in a pick-up truck later stormed into a home in another district close by, opening fire on a family of five.

Two men and a woman aged between 33 and 62 and a 16-year-old girl were killed, they said, while a 13-year-old girl was injured.

Police believe the same group killed two other Muslim men found dead at a nearby prayer house 500m away.

Suspected militants shot two other men while they were hunting animals in a forest in the early hours of Tuesday, also in Yala province. One of the men was killed instantly while the other was wounded and taken to hospital.

Tuesday is the fifth anniversary of the Krue Sae mosque incident, in which Thai security forces killed 32 men taking cover in the main mosque in Pattani province that neighbours Yala.

The raid, condemned by rights groups, took place after an uprising across all three restive southern provinces of Pattani, Yala and Narathiwat.

More than 3,600 people have been killed and thousands more injured in five years of separatist violence in the region.

Buddhist-majority Thailand annexed the ethnic Malay area in 1902, sparking decades of tension. -- AFP