At least six people have died after a car bomb detonated in Thailand's restive south.

Friday's attack comes after businesses received warnings not to open on the Muslim sabbath.

The suspects opened fire on a gold shop in Pattani province's Sai Buri district, hurting no one and fleeing,  Asis U-mayee, police colonel, said.

When security forces arrived at the scene, a bomb hidden in a gas canister in a nearby pickup truck went off, he said.

A border patrol volunteer, an administrative official and four civilians were killed. Twelve police officers were among the 44 people wounded.

Security officials said the pickup truck containing the bomb had been stolen in a September 7 attack in which three women were killed.

Friday's explosion set fire to buildings on both sides of the road in the town's commercial area, damaging rows of wooden shop houses.

Authorities said groups had distributed flyers in the past two weeks to warn local traders against operating their businesses on Fridays.

The attack came after a recent high-profile surrender of nearly 100 Muslim fighters to the Thai authorities.

There has been no claim of responsibility so far.

More than 5,000 people have been killed there over the past eight years in a Muslim separatist campaign.

Source: Agencies