Jamestown Foundation, 8 Sep 06: A Breakdown of Southern Thailand's Insurgent Groups
Thailand has faced an Islamist secessionist movement since 2001-2002 that has led to the deaths of more than 1,500 people. There have been nearly 400 successful bombings, many more attempted bombings and more than 400 arson attacks. Militants have assassinated more than 600 people. Ten of the 33 districts in the deep south are "plagued by violence" according to the Thai Ministry of the Interior, and the number is increasing. Yet, little is actually known about the insurgents' structure and capacity. To date, there has not been a single credible claim of responsibility, nor have the insurgents publicly stated their goals or political platform. Their unwillingness to disclose any details has worked to their advantage and left Thai intelligence in a quandary. There are a number of insurgent groups working together, and unlike the insurgency in the 1960s to the early-1990s, when groups were sharply divided over their goals and ideology and proved absolutely incapable of working together, today's organizations share a common Islamist agenda and are demonstrating unprecedented coordination and cooperation. No organization is trying to discredit another to build up its own power base...

The Pattani United Liberation Organization (PULO)

Barisan Revolusi Nasional-Koordinasi

Gerakan Mujahideen Islami Pattani (GMIP)

The Runda Kumpulan Kecil (RKK)

New PULO

Jemaah Salafi

...The preceding groups are responsible for the continuing insurgency in southern Thailand. The past few months have seen repeated coordinated bombing campaigns by these insurgents, such as an operation in June that involved more than 70 bombs, an operation on August 1 and the most recent operation on August 31 that targeted at least 20 commercial banks in Yala province. Coordination between the groups will continue to evolve as they pursue their shared Islamist agenda.
(group backgrounds at the link)