Thailand's south has been wracked by violence since January 2004, but the killing of over 100 mainly youthful Muslim militants by government forces on 28 April signified a sharp deterioration in the security situation in the majority-Muslim provinces of Narathiwat, Pattani and Yala. The harshness of the clampdown is likely to further alienate southern Muslims, who number 2.5 million or roughly 4% of Thailand's population. This could provide fertile ground for local separatist groups, as well as the Southeast Asia-wide terrorist network, Jemaah Islamiah.