A teacher has been shot and killed in front of a classroom of children in southern Thailand, according to police.
Security is tight in the restive southern provinces
Gunmen disguised themselves as students to shoot the Buddhist teacher at the primary school in Narathiwat district.
The attack is the latest in a string of violent incidents in the Thai south, where more than 1,300 people have been killed since January 2004.
Officials blames Muslim insurgents for much of the unrest, although criminal motives are also thought to be at work.
The southern provinces are predominantly Muslim, with a separate language and culture to much of the rest of Thailand.
Home to most of Thailand's 4% Muslim minority
Muslim rebels fought the government up to the mid-80s
Suspected militants have upped attacks since 2004, targeting Buddhists
Security forces' response criticised by rights groups
Police blamed militants for the killing of Prasarn Martchu, 46.
"He has taught at this school for 20 years and has no fight with anyone," police Colonel Bunleu Chawet said. "This is the work of insurgents."
The shooting prompted some 20 local schools to close indefinitely, an official said.
At least 30 teachers have been killed since the beginning of the insurgency.
Militants target schools and teachers because they see them as symbols of the Buddhist Thai authorities.
In many areas of the south, the government now provides teachers with armed escorts to and from their classes to prevent them from being harmed.
In June, five security officers escorting teachers to school were killed by a roadside bomb in neighbouring Yala province.