Thai-Australian teen stabbed to death in school fight

A 14-year-old has been arrested on charges alleging he stabbed a Thai-Australian schoolmate to death in a fight after a feud, police in Thailand say.

The suspect told investigators he and the victim harboured a mutual dislike from school and they agreed via the Line messaging app to meet outside a grocery store near their homes on Tuesday in Sattahip in Chonburi province, said the local police chief said on Friday.

The suspect appeared to have lost the fight because the other boy was bigger, but the suspect rushed to his car to grab a cooking knife and stabbed the victim in the back, said police Colonel Tanapol Klinkesorn, director of the Sattahip police station.

The victim was also 14, but the suspect was an eighth-grader while the victim was a year behind him, police said. They did not release their names because of their age but said the Australian Embassy confirmed the victim had dual nationality.

The boy was found lying at the entrance to the store with the knife in his back and its broken handle on the ground, according to Sawang Rojanatham Rescue Foundation, a charity organisation whose EMS workers rushed to the scene.

Tanapol said the suspect, accompanied by his parents, surrendered to Sattahip police about an hour after the stabbing.

Police charged him with causing fatal physical harm to another person and a weapons offence. He was release on 10,000 baht ($A270) bail on Wednesday by the Chonburi Juvenile and Family Court.

Police said the maximum sentence under the charges is 15 years' imprisonment, and that they are investigating the case further.

Adolescent violence is not rare in Thailand but fatal cases usually involve rival gangs of older students.

Sattahip is about 114km southeast of the capital Bangkok.