Flowers are laid at a Hat Yai shop where Saturday’s bomb blasts killed Canadian teacher Jessie Lee Daniel. The 29-year-old was among four killed and 70 injured in six simultaneous explosions detonated by suspected Islamic militants.

However, targeting areas beyond Hat Yai is still a long way off, security officials say.

The deputy commissioner of the Ninth Police Region, Maj-General Thani Thawidsri, said the attacks on Saturday night did not reflect the work and mindset of the vast majority of insurgents in the Malay-speaking South, which includes the provinces of Pattani, Yala and Narathiwat, and a couple of districts of Songkhla.

Authorities believe the Hat Yai bombings were carried out by a cluster of zealous operatives working under the leadership of Faisal Haji Isma-ae and Abdul Kamae Saleh.

The pair were linked to the Hat Yai Airport bombing in April last year, as well as the blitz in downtown Yala three months later. The latter incident featured a brief but deadly gunfight in the heart of Yala, as well as firebombs that torched a number of high-profile places, including a karaoke bar and a shopping complex.

Hat Yai is not far from the boundaries of the troubled Malay-speaking region - about 100km north of Pattani and about 50km east of Saba Yoi, a Malay-speaking district in Songkhla.

Thani, who has overseen the restive region for most of the past two decades, said it was important to understand that the current generation of militants in the deep South were organised into small independent cells of about five to eight people. There was no top-down, pyramidal chain of command and no suggestion that they could evolve into conventional guerrilla outfits with designated chains of command.

However, they had shown they can carry out simultaneous attacks.

More than 50 government offices and 22 banks have been hit in simultaneous bomb attacks in two separate incidents over the past three months. Officials say these were largely designed to discredit the government, rather than to damage for the sake of destruction. The bombs were small and contained no shrapnel.

But with their admission that insurgent violence in the deep South has now spread to the commercial hub of non-Malay-speaking Hat Yai, political leaders and security chiefs are effectively telling the public that the worst is yet to come.

From caretaker Deputy Prime Minister Chidchai Vanasatidya to police chief General Kowit Wattana, the official response is that the Hat Yai bombings were the work of Malay insurgents looking to separate the Malay-speaking South from the rest of the country. Yet the explosions that ripped through crowded bars and cafes, department stores, a hotel and a massage parlour in the tourist hub of Hat Yai were in an area that is not in the Malay-speaking South.

The bombs killed four people and injured more than 60, shattering the area's tourist industry and its business confidence, and raising implications far beyond the Muslim-majority region, where more than 1,700 people have been killed since January 2004.

Police have questioned more than 40 witnesses, but have yet to pin down any significant leads.

A leading security expert, Assoc Professor Panitan Wattanayagorn, said Saturday's attacks showed the coordination and capability of the group involved was much higher than authorities believed, although the tactics - bombs attached to motorbikes - were more or less the same.

He said the southern violence has crossed a new threshold because the choice of targets and the scale of the damage had far-reaching implications beyond the strife-torn region. And while the insurgency in the deep South may be home-grown, the separatists showed they had learned from foreign militant and terrorist groups that tend to go after high-profile places to create the greatest possible psychological impact, Panitan said.

"Repairing the economic infrastructure and the tourist industry is much harder than repairing damage inflicted on military and government targets," he said.

What was most worrying, Panitan said, was that every successful hit usually leads to a bigger attack, more lethal, efficient and precise than the first.

Don Pathan

The Nation