7 killed in violence in Thailand's south

In the deadliest incident insurgents ambushed a military convoy that was protecting teachers on their way to school early Tuesday in Yala, one of three Muslim-majority provinces on the southern border with Malaysia, police said.

A 20-kilogram (44 pound) bomb exploded under a military truck and killed a Buddhist soldier on the spot, police said. The blast left a crater two meters (six feet) deep.

Four Muslim men who volunteered as security officers survived the initial blast, but at least 20 militants waiting nearby then shot them in the head at point-blank range, police Colonel Jirasak Wikraicharoenying told AFP.

A second bomb exploded nearby just moments later. Jirasak said that explosion was meant to prevent security forces from rescuing the men.

Students in Narathiwat found a fourth bomb outside a school as they were arriving for classes but police defused it.

Insurgents often target schools and teachers because they are seen as imposing Thai Buddhist culture on a region that is mainly Muslim and ethnic Malay.