Security forces have discovered a large cache of assault rifles and ammunition buried in a rubber plantation in Narathiwat's Cho Airong district.
About 200 offices from the 48 Rangers Regiment and border patrol police carried out the search around 11pm Friday in the southern province. They unearthed five assault rifles, including four M16s and an AK, with seven magazines and 382 bullets, including M16 and AK rifle bullets, shotgun shells and M60 machine-gun bullets.
The weapons and ammunition were found in eight large fertiliser sacks and plastic bags, each one buried under a rubber tree, said Lt Col Issara Chantakrayom, deputy commander of the 48 Rangers Regiment.
The search was carried out after authorities interrogated a key figure from the Runda Kumpulan Kecil (RKK) separatist group, identified as Ruslan Salae, age 35. Ruslan, wanted on two arrest warrants, was arrested in Cho Airong on Thursday.
Officials also discovered four metal plates used for assembling an improvised explosive device (IED), as well as medicine, during the operation which took more than three hours.
A verification of the firearms showed three M16s had been stolen from the fourth military development unit in Cho Airong district in 2004.
All of the seized firearms were well-maintained and ready to use at any time, said Lt Col Issara.
When explosive ordnance disposal officers searched the site on Saturday morning, they found two more M16 rifles with 50 bullets, a backpack and a handheld ICOM radio, said Lt Col Issara.
Authorities believed Ruslan and his associates intended to use the weapons in planned attacks during the New Year holiday period.