Suspected insurgents killed at least 15 volunteer village defense officers and wounded four others in Thailand"s Muslim-majority south.

The late-night attack targeted a security checkpoint in southern Yala province. An unknown number of assailants then used explosives and scattered nails on roads to slow down a response from security forces.

"This is likely the work of the insurgents," Colonel Pramote Prom-in, a regional security spokesman said. "This is one of the biggest attack[s] in recent times".

Thailand"s three most southern provinces of Pattani, Narathiwat and Yala have faced a Malay-Muslim separatist insurgency since 2004 that has claimed nearly 7,000 lives.