A representative from the Army agreed to investigate the incident.

Hundreds of angry local residents gathered on a main road near the Pattani Central Mosque shortly after burying the 13- to 15-year-old victims of Friday's shooting.

They said the three victims and two other injured boys were playing tag on the road just metres away from where a weekly open market was set up at the time of the shooting.

The soldiers, dispatched to the area near Ban Bana to investigate the torching of four mobile-phone relay outlets, opened fire when they thought the boys were charging at them.

Local Army commander Colonel Wanchai Paungkhumsa initially said the soldiers had acted in self-defence, saying gunshots were fired from where a group of youths was standing.

"They could not just sit idly by in that situation," Wanchai was quoted by the Associated Press as saying.

However, a police source who spoke on condition of anonymity said no shots had been fired at the soldiers.

The bodies of the boys were paraded through the village and buried yesterday morning in line with Islamic tradition. Shortly afterwards, local residents took their demonstration to the heart of Pattani, where about 300 protesters, mostly young men, called for a thorough investigation into the shooting of the young unarmed men.

Panu, Colonel Wirawan Pathompark, deputy commander of the Internal Security Operation Command, and Pol Maj-General Korkiert Wongworachart, commander of Pattani Provincial Police, met with Marudin Cheka, a relative of the victims.

The two sides agreed that the 12-man unit involved in the shootings would be investigated and, if found to have acted inappropriately, transferred out of the three southernmost provinces. There will also be a public apology to Ban Bana residents if the investigation finds against the unit.

Local residents and observers said weeks of shooting deaths of unarmed young men by what appeared to be poorly trained security officials on the front line had threatened to bring sectarian violence to the restive region.

Human Rights Watch's representative in Thailand, Sunai Pasuk, said expectations from the Malay-speaking community had been high when Prime Minister Surayud Chulanont came to power.

"He promised to better handle the South, but in reality, security forces continue to use excessive force, resulting in many deaths. They continue to walk away from their crimes," Sunai said.

Last Monday, a government-backed village defence volunteer shot dead four unarmed Muslim youths following a heated exchange of words. The Army's decision to defend its actions drew a hail of criticism over the rules of engagement.

On March 9, a panel from the National Legislative Assembly was set up to investigate a shooting death after a group of rangers opened fire and launched an M79 grenade into a private Islamic boarding school in Yala's Ban Taseh. One student was killed and another injured while they were sleeping.

Initially, authorities said the school was not attacked but a bomb had accidentally gone off while students were practising making explosives.

Residents also suspected rangers of attacking another religious school in Songkhla's Saba Yoi district on March 17, killing three students and injuring seven others. A series of protests were held in the following weeks.

Media representatives and local Muslims accused the authorities of trying to cover up these attacks by giving the public false and misleading information.

Meanwhile in Yala, Buddhist residents yesterday continued to mourn the death of Patcharaporn Boonmart, 26, who was shot dead and burned by suspected insurgents on Wednesday.

Hundreds massed around her coffin, which was placed in front of Yala's main provincial hall.

Late yesterday evening, Surayud announced the cancellation of a scheduled briefing trip to the South with the press on April 20, citing the past week's escalating events as the cause.

However, the premier said he would attend Patcharaporn's cremation in Yala on Monday.

General Sonthi Boonyaratklin, chairman of the Council for National Security (CNS), meanwhile said he planned to organise a special trip to the deep South for the press to brief them on the latest situation and the policy of the CNS and the government for tackling the problems in the region.

In Narathiwat yesterday, two Muslim men aged 26 and 29 were gunned down by suspected militants in a drive-by shooting while they were riding a motorcycle. Also in Narathiwat, a 19-year-old Muslim boy was shot dead late on Friday in another drive-by shooting.

In Rusoh district, gunmen fired into a moving train, injuring two passengers. The State Railway of Thailand suspended services from Yala to Sungai Kolok district.

In another incident nearby, a fierce gun battle broke out between suspected insurgents and a ranger unit in the same tambon. The shooting lasted for about 10 minutes, police said.