Bangkok, Nov 6 (IANS): Suspected insurgents killed at least 15 people and wounded four others in Thailand's Muslim-majority south, police said on Wednesday. Media reports saif this is one of the biggest such attacks in the country recent times.

Insurgents struck three security posts in Yala province with firearms and explosives late on Tuesday night killing a dozen people, an official from the Internal Security Operations Command told Efe news on Wednesday. About half-a-dozen security men were injured, three of whom died later. The militants made way with their arms and ammunition.

"The areas surrounding the checkpoints have been closed off and are currently under forensic investigation, said a police officer.

The attacks are yet to be claimed by any of the rebel groups, as is usually the case in the region, reports Efe news.

Attacks and killings are common in the southern provinces of Pattani, Yala and Narathiwat despite the deployment of 40,000 security forces members and the impositions of states of emergency and martial law.

More than 7,000 people have been killed in the area since the Muslim separatist movement resumed its armed struggle in 2004 after a decade of relative calm, according to estimates of monitoring organization Deep South Watch.

Ethnic Muslim Malay Insurgents - the majority in the region - denounce discrimination suffered under the Buddhist government, demand more autonomy and even the creation of an independent state that integrates the three provinces. They formerly formed the Pattani Sultanate that Thailand annexed in 1909.