Local Muslims deny any part in the violence

The bomb was hidden in the fuel tank of a motorcycle outside a convenience store in Pattani province.

It was a similar device to one that killed two policemen in the city of Pattani earlier this month.

A series of attacks in the south have been blamed by ministers on both Muslim separatists and bandits.

Police said they thought that the bomb discovered in the motorcycle was intended to detonate while officers were inspecting it

SOUTHERN THAILAND Home to most of Thailand's 4% Muslim minority Muslim rebels fought the government up to the mid-80s Area beset by poverty and poor relations between local communities and officials Thailand wakes to separatist threat

"It was likely done by someone who wants to create unrest in the province, as several places in Pattani have been warned of being possible targets for the unrest," said police colonel Chaithat Inthanoochit.

Six people have been killed in violence this month including four soldiers who were killed when gunmen raided an arms depot in Narathiwat province.

Two policemen were also injured in a raid on a police station in Yala province.

Police say they have so far arrested four people in connection with the Yala attack including a Malaysian.

The series of attacks prompted the declaration of martial law in the three provinces of Pattani, Yala and Narathiwat.

There have been contradictory statements by the government linking the violence to both Muslim separatists and bandits.

The three provinces are home to most of Thailand's six million Muslims, who make up about 4% of the population.