Each morning, Buddhist monks wrap themselves in saffron-colored robes and silently stroll, collecting alms in Thailand's three southern provinces while a phalanx of troops armed with assault rifles walk alongside, protecting them from Islamist assassins.

Buddhist and anti-separatist Muslim teachers suffer a similar deadly fate in the south, despite military escorts to and from campus, armed soldiers posted inside classrooms, and official permission for every teacher to carry a gun. In the grim struggle, which escalated in 2004, more than 4,700 people on all sides -- Buddhists and Muslims -- have been killed plus 9,000 injured.

On Sept. 6, suspected Islamist guerrillas shot dead a school teacher, poured gasoline on his body and set him on fire in Yala province, Police Lt. Col. Krisanapong Paetsith said after shocked villagers discovered the corpse in flames on the side of a road. The teacher had been executed with a bullet to the head. He had been riding his motorcycle, which lay abandoned nearby, after helping students in an academic contest.

The military has also set up fortified outposts along the graceful walls of Buddhist temples in the south to safeguard monks and worshippers amid shrines and statues of the Buddha, where troops also detain suspects for questioning. But often the military is thwarted, as on Aug. 23, when an improvised explosive device injured one monk, nine soldiers and three civilians in Pattani province, despite 15 soldiers escorting the monks and young novices returning to their temple, police said. The remote-controlled bomb was hidden in a five-kilogram cooking gas cylinder in an untended pushcart, which had been used to sell fried chicken. The same day, in neighboring Yala province, a bomb at a bridge killed two paramilitary rangers on a motorcycle.

Muslim guerrillas bomb, shoot, stab and behead government officials, teachers, moderate Muslims, rubber plantation workers, shopkeepers, restaurant owners, hoteliers, businessmen, Buddhist monks, worshippers and others to force an exodus of residents who oppose the Islamists' demands for autonomy or independence in the south. But on the other side, army and police in the mountainous jungle region unleash their assaults with mixed results, amid documented reports of extrajudicial killings, torture, kidnapping, wrongful imprisonment and other human rights violations.

In July, a court ordered the army, defense ministry and police to pay US$175,000 to the family of a Muslim religious teacher who was killed in military custody while undergoing violent interrogation for two days in 2008. Yapa Koseng, 56, had been arrested for suspected links to the guerrillas, but the court ruled the imam was not involved with the insurgency.

Thailand's new Prime Minister Yingluck Shinawatra, who was elected on July 3, now faces a seemingly intractable war. The violence is mostly confined to the three southern provinces of Pattani, Yala and Narathiwat where ethnic Malay-Thai Muslims comprise a 95 percent majority of the region's 1.7 million population along Thailand's border with Muslim-majority Malaysia.

Politicians and the military denounce the Islamist guerrillas as greedy and corrupt Muslims, allied to criminal gangs, who want to terrorize Buddhists and Muslims, seize their property, and create anarchy so they can smuggle drugs, weapons and other black market items.

"Those who subscribe to a true separatist ideology make up only 20 percent of the insurgents. The rest are drug traffickers and oil smugglers who stage insurgent violence," said Lt. Gen. Udomchai Thammasarorat, the army chief in charge of the military's assaults in the south. "Every time they deliver drugs, they will plant bombs to divert the authorities' attention," he said in August.

Independent analysts, however, say the Islamists want political, ideological and economic control over the region's profitable rubber plantations, coastal fishing industry and other natural resources, and to dominate the population under sharia law.

To avoid discovery, the guerrillas keep themselves hidden, do not identify any leader or spokesman, and do not claim credit for successful attacks except for occasionally scattering printed warnings about their vengeance.

Investigators link most attacks to the Barisan Revolusi Nasional Coordinate (BRN-C), or National Revolutionary Front-Coordinate, which is rooted in the pan-Arab Islam of the 1960s. The BRN-C appears to use mosques and Muslim "pondok" schools to spread a fundamentalist Islamic doctrine, and operates a village-based cell structure to ensure confidentiality which has enabled it to become the Thai military's most difficult and deadly enemy.

Another group, the Pattani United Liberation Organization (PULO), was founded in 1968 but now has its main spokesman Kasturi Mahkota based in Sweden. Critics say PULO has no control over the south's new generation of increasingly hard-line Islamist guerrillas.

Rival groups have also staged attacks, but have grown weaker over the past two decades due to arrests, deaths, defections and splits. Graffiti and pamphlets by various Islamists herald the revival of an independent Pattani, which they describe as a prosperous Malay sultanate before it was invaded in 1786 by northern Buddhists.

In 1909, British colonialists arranged for the territory to be annexed by Bangkok, which curbed the Muslims from emphasizing their Malay dialect and history, and boosted the use of Thai language and a sanitized, nationalistic storyline. But the dream of a "liberated" Pattani has not disappeared. When an appeals court on July 27 upheld a life sentence for rebellion against an Islamist guerrilla, Rosdi Mayama, it said he was terrorizing southerners to create an independent Pattani nation. Prosecutors said Rosdi organized rebels to bomb targets and execute informants.

Some Malay-Thai insurgents fought in Afghanistan during the Soviet occupation in the 1980s and chaotic aftermath of the 1990s, while some Muslim clergy were influenced by a puritanical Salafi or Wahhabi theology, which dates back to Islam's earliest followers and remains inspirational in some Arab nations.

Other Malay-Thai rebels have loose links with guerrillas in neighboring Indonesia and the Philippines. But US and independent investigators have not found any major relationship with al Qaeda or other foreign-based jihadists, and describe Thailand's war as home-grown and localized mostly to the south.

The army insists its 60,000 troops in the south have whittled the rebels to less than 5,000 fighters, but the guerrillas seemingly attack at will -- often several times a week -- and usually escape.

Thailand's senior generals meanwhile are more often focused on the disastrous ramifications of their opportunistic 2006 coup and ensuring military promotions, lucrative procurement contracts, and legal immunity for their actions in the south and elsewhere, despite the war's urgency.

The U.S., however, has been warning of Bangkok's mistreatment of southern Muslims.

"Apart from a distinct regional identity based on the historical Kingdom of Pattani, the southern insurgency is fueled by a communal sense of grievance based on an overall lack of justice," the U.S. Embassy wrote in a March 20, 2009 confidential cable to Washington released by the anti-secrecy website WikiLeaks.

"The police and judiciary have historically been part of the problem in the deep south," said the cable, signed by then-U.S. Ambassador Eric John. "Corrupt and abusive police units, coupled with a weak and opaque judicial system, have inflamed the long-standing animosity of majority Malay-Muslim population towards the central government. As these institutions have exacerbated the problems in the South, their reform is crucial to any RTG [Royal Thai government] effort end the violence," it said.

"We have a guidance in the embassy: 'No boots on the ground in the south.' That means no military people down there," said Randall D. Bennett, Senior Regional Security Officer at the American Embassy in Bangkok in a rare public description of U.S. government anti-terrorist activity in the south.

"If we go, we go down without profile. We go down from point A to point B. We don't wander around. It's kind of an invisible presence," Mr. Bennett said in a news conference last year.

When Thailand's military invited him to the southern war zone, "I went straight to Hat Yai, they flew me into the Yala base, and I met with the senior command, and we had a lot of good discussions about terrorism and ways that you can win people over," Mr. Bennett said.

"We have a program called the Anti-Terrorism Assistance Program, where we provide about 12 courses, every year, to royal Thai police and royal Thai government officials in a wide range of topics that typically are somehow anti-terrorism related."

That program is officially known as Diplomatic Security Anti-Terrorist Training and includes "training in intelligence, VIP protection, canine operations, small arms, and similar subjects," according to the 2009 U.S. Embassy cable.

During 2009 and 2010, "I think we've had about 30 courses. So we bring a lot of the southern force people up here, the leaders, the commanders, and we train them here, and then they go back," Mr. Bennett said.

"We are very concerned, we are very interested, but this is an internal insurgency."