Thai officials say 112 people have been killed in clashes between security forces and militants who attacked more than a dozen security posts in three southern provinces.
Thai armed forces Commander Chaiyasith Shinawatra issued the casualty figures adding that 17 attackers were captured and are being questioned.
General Chaiyasith said most of the attackers were in their twenties and their leaders wore black T-shirts - indicating a high level of organization. He added his troops seized knives, guns, and explosives.
Officials believe the attackers wanted to steal weapons, as in a similar attack in January on an army barracks in which four soldiers were killed. That incident set off the latest wave of violence and prompted the Thai government to declare martial law in three mostly Muslim, southern provinces.
The spokesman for Prime Minister Thaksin Shinawatra, Jakrapob Penkair, says the government believes the unrest is not due to religious extremists, but rather criminals seeking to cover up their illegal activities.
"There are many people in the south that have been involved with illegitimate businesses, like drugs and illegal products crossing the border [smuggling]," he said. "And these people have been depending on the situation in the south for a long time to camouflage their illegal businesses."
Officials, at other times, have blamed the violence on Muslim separatists who are unhappy over poverty and discrimination under the central government of predominantly Buddhist Thailand.
Professor Ron May, an expert on Southeast Asian Islamic movements at Australia National University, says the militants may be connected to international terrorist groups such as Jemaah Islamiyah.
"JI and other groups have been operating in Southern Thailand and as the Army has moved in there have been increasing clashes," he said.
But no one has been able to accurately describe the attackers or their ideology, if they have one.
The clashes were the bloodiest in years.
In the 1970s, Muslim separatists launched a low-grade insurgency but this ended in the late 1980s with a general amnesty. The attacks flared again in January and since then about 70 people have died, mostly in drive-by killings by men on motorcycles.