Thailand, Nov. 6 -- At least 15 people, including a police officer and many village defence volunteers, have been killed in an attack on a security checkpoint in southern Thailand.

The incident is the worst single attack in years. Thousands of people have been killed in the region ravaged by a decade-old separatist campaign.

The attackers, in the province of Yala, also used explosives and scattered nails on roads to delay pursuers.

An army spokesman Colonel Pramote Prom-in said on Wednesday that 12 were killed at the scene, two more died at the hospital and one died this morning. Five others were wounded, adding that the attackers took M-16 rifles and shotguns from the checkpoint.

"This is likely the work of the insurgents," he said. ...