A bomb blast killed two top provincial officials on Friday in Thailand's insurgency-plagued south, authorities said, blaming the attack on rebel fighters seeking to derail peace talks.

The deputy governor of Yala province, Issara Thongthawat, was killed along with Yala permanent secretary responsible for security, Chavalit Krairisk, after a roadside bomb struck their vehicle, officials said.

Issara, 56, was rushed to hospital but later died, army spokesman Colonel Pramote Promin told AFP by telephone.

He said the deputy governor appeared to have been targeted by militants while on his way to attend a local food fair.

"Explosive material was put inside a gas cylinder and hidden under the road," he said. "His driver is still in critical condition."

More than 5,500 people have been killed in nine years of bloodshed in Thailand's Muslim-majority south near the border with Malaysia, with shadowy insurgent groups blamed for near-daily bombings and shootings.

Security personnel and those connected with the government are regularly targeted, as well as Muslims perceived to be collaborating with the authorities.

Thailand held its first official peace talks with southern insurgents last week, with a one-day meeting with representatives of the Barisan Revolusi Nasional in Malaysia's capital Kuala Lumpur.

But while talks were said to be cordial -- and a further round was set for April 29 -- attacks have continued in the region.

Thai National Security Council chief Paradorn Pattanatabut, who headed the government delegation, said the bomb blast would not jeopardise the next round of talks.

"Dialogue must go ahead while strict security measures must be taken to protect officials and public lives and property," he told AFP.

"This is the work of people who do not support peace talks and want the process to stall," he said.
Little is known about the various militant groups' identities, structures or aims, and questions remain over the ability of older militant leaders to rein in attacks by a younger generation of insurgents.

Earlier this week, a Thai marine was abducted from his home and killed in what police described as a revenge attack by militants who carried out a botched raid on a military base in February in which 16 rebel fighters were killed.

His blindfolded body was found on a village road with two gunshot wounds and his hands bound.

Thai Prime Minister Yingluck Shinawatra said afterwards that the marine's death would not undermine the peace dialogue, saying it would take time to build confidence.